CN111951987B - Small modular reactor coolant system and experimental method applying same - Google Patents

Abstract

The invention discloses a small modular reactor coolant system, wherein liquid gallium metal is used as a coolant in the system, a certain amount of gas is added into the coolant, the natural circulation capacity of the liquid gallium metal is increased through the gas, the disturbance of the liquid gallium metal can also be increased, and the heat exchange effect is enhanced; through the system, the liquid gallium metal can be increased or reduced repeatedly, the doped gas can be increased or reduced at will, the air pressure is adjusted, the heat exchange capacity and the natural circulation capacity of the liquid gallium metal under various conditions are recorded and analyzed, and basic data are provided for building flexible and diverse small modular reactors.

Description

A small modular reactor coolant system and an experimental method using the same

technical field

The invention relates to the field of nuclear energy, in particular to a small modular reactor coolant system.

Background technique

With the continuous growth of energy demand and the continuous strengthening of environmental protection awareness, the role of nuclear reactors has become more and more prominent. The rapid development of nuclear reactors also poses challenges to the thermal conductivity of the reactor coolant and the safety of the reactor. From the current point of view, most of the nuclear reactors in the world are pressurized water reactors, which use water as the reactor core coolant. However, in recent years, the research on the use of liquid metal as the reactor core coolant is constantly being carried out. . Compared with pressurized water reactors, liquid metal coolant reactors have better natural circulation capability, greater power density, operate at low pressure, have better inherent safety, smaller size and more compact system. The research on the three metals sodium metal, lead and lead-bismuth alloy as the reactor core coolant is the most abundant, but there is little research on the use of liquid metal gallium as the reactor core coolant, and no small amount of gas is added to the liquid metal gallium. After the cycle capacity, thermal conductivity and other aspects of research.

In order to improve the flexibility of the reactor, small modular reactors are developing rapidly, which have the advantages of integrated design, modular installation, high safety, wide applicability, short construction period and low one-time investment. The scheme of combining small modular reactors will also be the focus of future development. On this basis, it is particularly important to study and obtain the relevant parameters of modular reactors using liquid metal gallium as the coolant, especially the research on the performance of the coolant.

Due to the above reasons, the inventors have conducted in-depth research on the existing research plans for the performance of the reactor coolant, expecting to design a small modular system for studying the circulation capability and thermal conductivity of the liquid metal gallium coolant that can solve the above problems. Reactor coolant system.

SUMMARY OF THE INVENTION

In order to overcome the above-mentioned problems, the inventors have carried out keen research and designed a small modular reactor coolant system. In the system, liquid metal gallium is used as the coolant, a certain amount of gas is added to the coolant, and the liquid metal is added to the coolant through the gas. The natural circulation ability of gallium metal can also increase its disturbance and enhance the heat transfer effect; through this system, the liquid gallium metal can be repeatedly increased or decreased, and the doped gas can also be arbitrarily increased or decreased, the air pressure can be adjusted, and various conditions can be recorded and analyzed. The heat transfer capability and natural circulation capability of the lower liquid gallium metal provide basic data for building flexible and diverse small modular reactors, thereby completing the present invention.

Specifically, an object of the present invention is to provide a small modular reactor coolant system including a reactor pressure vessel, a main pump and an intake tank;

Wherein, a coolant inlet and a coolant outlet are arranged on the wall of the reactor pressure vessel;

A reactor core is arranged below the inside of the reactor pressure vessel, and a steam generator is arranged above the inside of the reactor pressure vessel,

The liquid outlet of the main pump is connected to the coolant inlet through the coolant pipeline, and the liquid inlet of the main pump is connected to the coolant outlet through the coolant pipeline;

The intake box is communicated with the coolant pipe through an air extraction pump.

Wherein, below the reactor pressure vessel, a coolant descending ring segment is arranged around the core, one end of the coolant descending ring segment is connected to the coolant inlet, and the other end of the coolant descending ring segment is connected to the reactor the bottom of the pressure vessel,

The core is provided with passages through which the coolant flows, the passages communicating from the bottom of the reactor pressure vessel to the steam generator,

A heat exchange tube is provided in the steam generator,

One end of the heat exchange tube is communicated with the channel in the core, and the other end is communicated with the coolant outlet.

Wherein, the heat exchange tube is a spiral heat exchange tube, and heat transfer fins are provided on the outer surface of the heat exchange tube.

Among them, the system also includes a surge tank and a gas storage tank,

The pressure-stabilizing tank is provided with a sealing baffle, and the sealing baffle can move back and forth in the pressure-stabilizing tank and maintain a sealed contact with the inner wall of the pressure-stabilizing tank;

The sealing partition divides the surge tank into a lower air chamber and an upper mixing chamber;

the air cavity is in communication with the coolant pipe;

The mixing chamber is communicated with the gas storage tank.

Wherein, the air storage tank is also communicated with the air intake box 3;

Preferably, a pressurization system is provided on the pipeline connecting the air storage tank and the mixing chamber, and a pressurizing system is also provided on the pipeline connecting the air storage tank and the intake box;

Preferably, the booster system includes a booster pump and a compressor.

Wherein, the pressurization system is used to control the air pressure value in the air chamber, and then control the air pressure value in the mixing chamber.

Wherein, the suction pump is used to transport the gas in the intake box to the coolant pipeline;

The suction pump is also used to deliver the gas in the coolant pipeline to the intake tank.

Among them, the system also includes a liquid metal gallium storage tank,

The liquid metal gallium storage tank is communicated with a coolant pipeline, and a feed pump and a valve are arranged on the communication pipeline.

Preferably, the feed pump is used to pump the liquid gallium from the liquid metal gallium storage tank into the coolant pipeline,

The feed pump is also used to pump the liquid gallium from the coolant line into the liquid metal gallium storage tank.

Among them, a heater is arranged in the liquid metal gallium storage tank,

The metal gallium stored in the liquid metal gallium storage tank is continuously heated by the heater, so that the temperature of the metal gallium is maintained above 30 degrees Celsius, and the metal gallium is in a liquid state.

The present invention also provides an experimental method for obtaining the heat transfer performance of liquid gallium, which is realized by the small modular reactor coolant system described herein;

Preferably, the method includes an experimental preparation process, an experimental process and an inter-experiment processing process:

The experimental preparation process includes the following sub-steps:

Sub-step 1, start the feed pump 91, and inject the liquid metal gallium into the coolant pipeline 4;

Sub-step 2, open the booster system 8 between the air storage tank 7 and the air intake box 3, pump the gas into the air intake box 3, then open the air suction pump 5, and pump the gas into the coolant pipeline 4;

Sub-step 3, open the pressurization system 8 between the surge tank 6 and the gas storage tank 7, and control the gas pressure of the air cavity 62 above the sealing baffle 61 in the surge tank 6, thereby reducing the gas pressure in the coolant pipe 4. Adjust to the experimental preset air pressure value until the pressure and gas volume in the coolant pipeline 4 meet the requirements;

The experimental process includes the following sub-steps:

Sub-step a, start the main pump 2 to make the metal gallium coolant circulate in the coolant pipeline 4;

Sub-step b, when the coolant circulation is stable, start the reactor core to make the reactor work normally;

The inter-experiment processing process includes the following sub-steps:

Sub-step A, the gas in the coolant pipeline 4 is drawn into the air intake box by the air pump 5;

Sub-step B, start the main pump 2 to promote the coolant circulation, and open the core to ensure that the temperature of the liquid metal gallium in the coolant pipeline is maintained above 40 degrees.

The beneficial effects of the present invention include:

(1) In the small modular reactor coolant system provided by the present invention and the experimental method for applying the same, by adding gas to the liquid gallium metal to increase the natural circulation capacity of the liquid gallium metal, it can also increase its disturbance and enhance the heat exchange effect. ;

(2) According to the small modular reactor coolant system provided by the present invention and the experimental method for applying the same, the usage amount of the coolant liquid gallium metal can be adjusted at any time, so that when the gas is increased, the usage amount of the liquid gallium metal can be appropriately reduced;

(3) According to the small modular reactor coolant system provided by the present invention and the experimental method using the same, the amount of gas added to the coolant can be adjusted at any time, so as to find the best combination ratio of gas and coolant.

Description of drawings

FIG. 1 shows a schematic diagram of the overall structure of a small modular reactor coolant system according to a preferred embodiment of the present invention.

Description of reference numbers:

1 - Reactor pressure vessel

11-Coolant inlet

12 - Coolant outlet

13-core

14-Steam generator

2-Main pump

3- Intake box

4- Coolant piping

41-Coolant drop ring section

42-Heat exchange tube

5-Aspiration pump

6-Pressure tank

61-Sealing diaphragm

62-air chamber

63-Mixing chamber

7-Gas tank

8-Pressurization system

9-Liquid metal gallium storage tank

91-Feed pump

92-valve

93-Heater

Detailed ways

The present invention will be further described in detail below through the accompanying drawings and embodiments. The features and advantages of the present invention will become more apparent from these descriptions.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. While various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

The small modular reactor coolant system provided according to the present invention, as shown in FIG. 1 , includes a reactor pressure vessel 1 , a main pump 2 and an intake tank 3 .

Wherein, a coolant inlet 11 and a coolant outlet 12 are provided on the wall of the reactor pressure vessel 1;

A core 13 is arranged under the interior of the reactor pressure vessel 1, and a steam generator 14 is arranged above the interior of the reactor pressure vessel 1. The core 13 is used to heat the coolant, and the core 13 can be A large amount of heat is generated in a short period of time, providing extremely high temperatures, and the core can be made from nuclear reactor fuel rods or conventional energy sources.

The liquid outlet of the main pump 2 is connected to the coolant inlet 11 through the coolant pipeline 4, and the liquid inlet of the main pump 2 is connected to the coolant outlet 12 through the coolant pipeline 4;

The intake box 3 communicates with the coolant pipe 4 through an air suction pump 5 .

Preferably, below the interior of the reactor pressure vessel 1, a coolant descending ring segment 41 is provided around the core 13, one end of the coolant descending ring segment 41 is communicated with the coolant inlet 11, and the coolant descending ring The other end of the section 41 is connected to the bottom of the reactor pressure vessel 1 .

The core 13 is provided with a channel for the coolant to flow through, the channel is communicated from the bottom of the reactor pressure vessel 1 to the steam generator 14, and a heat exchange tube 42 is provided in the steam generator 14. One end of the tube communicates with the channel in the core 13 and the other end communicates with the coolant outlet 12 .

Through the above arrangement, a closed-loop circulation pipeline of the coolant is formed, and the coolant flows through the core 13 to obtain heat under the driving of the main pump, and carries the heat to the steam generator 14, where the heat is dissipated, and then flows back to the steam generator. to the main pump for the next cycle.

Preferably, the reactor pressure vessel 1 can be set to any size, the diameter of the coolant pipe 4 can be 1cm to 100cm, and the pipe shape can be a circular pipe, a square pipe or a diamond pipe, preferably, the coolant pipe The inlet temperature is 200°C to 300°C, and the outlet temperature is 400°C to 500°C.

In a preferred embodiment, the heat exchange tubes 42 are spiral heat exchange tubes, and heat transfer fins are provided on the outer surfaces of the heat exchange tubes 42 . By setting the spiral heat exchange tube to increase the heat exchange area and improve the heat exchange efficiency, further setting the heat transfer fins on this basis can further enhance the heat exchange capacity and ensure that the heat generated by the reactor is transferred to the feed water or steam in time. circuit coolant.

Preferably, the material of the coolant channel and the heat exchange tube is selected from a material with excellent corrosion resistance, so as to avoid corrosion of metal gallium.

In a preferred embodiment, the system further includes a surge tank 6 and a gas storage tank 7 , and a seal baffle 61 is provided in the surge tank 6 , and the seal baffle 61 can move back and forth in the surge tank 6 , and keep in sealed contact with the inner wall of the surge tank 6;

The sealing baffle 61 divides the surge tank 6 into an air cavity 62 located below and a mixing cavity 63 located above; the air cavity 62 is communicated with the coolant pipeline 4; the mixing cavity 63 is connected to the air storage tank 7 Connected.

Through the arrangement of the surge tank 6, the gas pressure in the coolant pipeline can be conveniently controlled, thereby obtaining the heat exchange performance and natural circulation capability of the coolant under different gas pressure conditions.

The gas tank is the common gas source of the surge tank and the air intake box, which simplifies the equipment of the reactor, reduces the volume of the reactor, and simplifies the operation process.

Preferably, in order to record the heat exchange performance and natural circulation capability of the coolant, a temperature sensor and a flow meter are provided at the secondary circuit coolant of the steam generator to calculate the transferred heat.

During the experiment, the main pump can be suddenly turned off at any time, so that the coolant loses the power of active flow. At this time, the coolant will perform a natural circulation flow, and the natural circulation flow will be intensified under the action of the gas. The flow rate, heat transfer efficiency and other related parameters of the coolant can quantitatively analyze the natural circulation capacity of the coolant. By adjusting the ratio of replacement gas and liquid gallium, the optimal performance parameters under various working conditions can be obtained.

In a preferred embodiment, the gas storage tank 7 is also communicated with the intake box 3; a pressurization system 8 is provided on the pipeline connecting the gas storage tank 7 and the mixing chamber 63,

A booster system 8 is also provided on the pipeline connecting the air storage tank 7 and the air intake box 3;

Preferably, the booster system 8 includes a booster pump and a compressor.

The booster system 8 is used to control the air pressure value in the air chamber 62 , and then control the air pressure value in the mixing chamber 63 . The pressurization system can control the air pressure in the coolant pipeline, so as to give the experimental results under different air pressure conditions, and provide a data basis for the design of small modular reactor pressure.

In a preferred embodiment, the suction pump 5 is used to transport the gas in the intake box 3 to the coolant pipeline 4; the suction pump 5 is also used to transport the gas in the coolant pipeline 4 to the intake In the air box 3, that is, the gas content in the coolant pipeline can be controlled by the air pump, which provides a data basis for repeated experiments; the gases described in this application are inert gases, such as helium, nitrogen, and argon. Can be a mixture of helium, nitrogen and argon.

In a preferred embodiment, the system further includes a liquid metal gallium storage tank 9, the liquid metal gallium storage tank 9 communicates with the coolant pipeline 4, and a feed pump 91 and a valve 92 are provided on the communication pipeline.

Preferably, the feed pump 91 is used to pump the liquid gallium from the liquid metal gallium storage tank 9 into the coolant pipeline 4,

The feed pump 91 is also used to pump the liquid gallium from the coolant line 4 into the liquid metal gallium storage tank 9 . By arranging the feed pump 91 and the gallium metal storage tank 9, the coolant can be replenished to the coolant pipeline at any time, or the coolant can be withdrawn from the coolant pipeline, so as to conveniently adjust the amount of coolant in the coolant pipeline.

In a preferred embodiment, a heater 93 is provided in the liquid metal gallium storage tank 9,

The metal gallium stored in the liquid metal gallium storage tank 9 is continuously heated by the heater 93 so that the temperature of the metal gallium is maintained above 30 degrees Celsius, and the metal gallium is in a liquid state. Preferably, the liquid metal gallium storage tank 9 is controlled by the heater 93 The temperature of gallium in metal is maintained above 50 degrees Celsius.

The present invention also provides an experimental method for obtaining the heat transfer performance of liquid gallium, which is realized by the above-mentioned small modular reactor coolant system;

Preferably, the method includes an experimental preparation process, an experimental process and an inter-experiment processing process:

Experiment preparation process: start the feed pump 91 and inject the liquid metal gallium into the coolant pipeline 4. When the injection amount meets the experimental requirements, open the pressurization system 8 between the gas storage tank 7 and the air intake box 3, and inject the gas Pump into the air intake box 3, then turn on the air pump 5, pump an appropriate amount of gas into the coolant pipeline 4, and then open the booster system 8 between the surge tank 6 and the gas storage tank 7 to control the pressure inside the surge tank 6. The gas pressure of the gas cavity 62 above the sealing baffle 61 is adjusted to adjust the gas pressure in the coolant pipe 4 to the experimental preset gas pressure value. When the pressure and gas volume in the coolant pipe 4 meet the requirements, the valve 92 for conveying metal gallium is closed, and the gas valve between the air pump 5 and the coolant pipe 4 is closed at the same time.

Experimental process: Start the main pump 2 to make the metal gallium coolant circulate in the coolant pipeline 4. When the coolant circulation is stable, start the reactor core to make the reactor work normally.

Preferably, when the reactor is working normally, the coolant will be pushed by the main pump, flow through the coolant descending ring section 41, collect at the bottom of the reactor pressure vessel 1, and then turn upward to flow through the core 13, absorb the heat of the core 13 and continue Flowing upward, heat is exchanged through the heat exchange tube when flowing through the steam generator 14, and the coolant whose temperature has been lowered flows out of the steam generator 14 and flows into the main pump 2 again to complete a cycle.

During the experiment, after the reactor is working normally, observe and record data such as the flow rate of the coolant, heat transfer efficiency, air pressure in the coolant pipeline, etc., to judge the working performance of the coolant when the reactor is working normally;

Stop the main pump 2, continue to record the coolant flow speed, heat transfer efficiency, air pressure in the coolant pipeline and other data to judge the natural circulation flow capacity of the coolant when a fault occurs.

During the treatment process between experiments, the gas in the coolant pipeline 4 is extracted into the intake box by the air pump 5;

The liquid metal gallium in the coolant pipeline 4 is pumped into the liquid metal gallium storage tank through the feed pump, or the main pump 2 is started to promote the circulation of the coolant, and the core is opened slightly to ensure the temperature of the liquid metal gallium in the coolant pipeline. Keep it above 40 degrees.

The present invention has been described above with reference to the preferred embodiments, but these embodiments are only exemplary and serve only for illustrative purposes. On this basis, various substitutions and improvements can be made to the present invention, which all fall within the protection scope of the present invention.

Claims (12)

1. A small modular reactor coolant system, characterized in that the system comprises a reactor pressure vessel (1), a main pump (2) and an air intake box (3); Wherein, a coolant inlet (11) and a coolant outlet (12) are provided on the wall of the reactor pressure vessel (1); A core (13) is arranged below the interior of the reactor pressure vessel (1), a steam generator (14) is arranged above the interior of the reactor pressure vessel (1), The liquid outlet of the main pump (2) is connected to the coolant inlet (11) through the coolant pipeline (4), and the liquid inlet of the main pump (2) is connected to the coolant outlet through the coolant pipeline (4) (12); The air intake box (3) is communicated with the coolant pipeline (4) through an air suction pump (5); The system also includes a liquid metal gallium storage tank (9), The liquid metal gallium storage tank (9) is communicated with the coolant pipeline (4), and a feed pump (91) and a valve (92) are arranged on the communication pipeline; The feed pump (91) is used to pump the liquid gallium from the liquid metal gallium storage tank (9) into the coolant pipeline (4), The feed pump (91) is also used to pump the liquid gallium from the coolant line (4) into the liquid metal gallium storage tank (9). 2. The small modular reactor coolant system of claim 1, wherein: Below the reactor pressure vessel (1), a coolant descending ring segment (41) is arranged around the core (13), and one end of the coolant descending ring segment (41) communicates with the coolant inlet (11). , the other end of the coolant descending ring segment (41) is connected to the bottom of the reactor pressure vessel (1), A channel for coolant to flow through is provided in the core (13), and the channel communicates from the bottom of the reactor pressure vessel (1) to the steam generator (14), A heat exchange tube (42) is provided in the steam generator (14), One end of the heat exchange tube is communicated with the channel in the core (13), and the other end is communicated with the coolant outlet (12). 3. The small modular reactor coolant system of claim 2, wherein: The heat exchange tube (42) is a spiral heat exchange tube, and heat transfer fins are provided on the outer surface of the heat exchange tube (42). 4. The small modular reactor coolant system of claim 1, wherein: The system also includes a surge tank (6) and a gas storage tank (7), The pressure-stabilizing tank (6) is provided with a sealing partition (61), the sealing partition (61) can move back and forth in the pressure-stabilizing tank (6), and is kept sealed with the inner wall of the pressure-stabilizing tank (6) touch; The sealing partition (61) divides the surge tank (6) into an upper air chamber (62) and a lower mixing chamber (63); the air cavity (62) communicates with the coolant pipe (4); The mixing chamber (63) communicates with the gas storage tank (7). 5. The small modular reactor coolant system of claim 4, wherein: The air storage tank (7) is also communicated with the air intake box (3). 6. The small modular reactor coolant system of claim 5, wherein: A pressurization system (8) is arranged on the pipeline connecting the gas storage tank (7) and the mixing chamber (63), A supercharging system (8) is also arranged on the pipeline connecting the air storage tank (7) and the air intake box (3). 7. The small modular reactor coolant system of claim 6, wherein: The booster system (8) includes a booster pump and a compressor. 8. The small modular reactor coolant system of claim 6, wherein: The pressure boosting system (8) is used to control the air pressure value in the air chamber (62), thereby controlling the air pressure value in the mixing chamber (63). 9. The small modular reactor coolant system of claim 1, wherein: The air suction pump (5) is used to transport the gas in the air intake box (3) to the coolant pipeline (4); The air suction pump (5) is also used to transport the gas in the coolant pipe (4) to the intake box (3). 10. The small modular reactor coolant system of claim 1, wherein: A heater (93) is arranged in the liquid metal gallium storage tank (9), The metal gallium stored in the liquid metal gallium storage tank (9) is continuously heated by the heater (93), so that the temperature of the metal gallium is maintained above 30 degrees Celsius, and the metal gallium is in a liquid state. 11. An experimental method for knowing the heat transfer performance of liquid gallium, characterized in that, The method is realized by a small modular reactor coolant system as claimed in one of the preceding claims 1-10. 12. The experimental method for knowing the heat transfer performance of liquid gallium according to claim 11, characterized in that, The method includes the experimental preparation process, the experimental process and the inter-experiment processing process: The experimental preparation process includes the following sub-steps: Sub-step 1, start the feed pump 91, and inject the liquid metal gallium into the coolant pipeline 4; Sub-step 2, open the booster system 8 between the air storage tank 7 and the air intake box 3, pump the gas into the air intake box 3, then open the air suction pump 5, and pump the gas into the coolant pipeline 4; Sub-step 3, open the pressurization system 8 between the surge tank 6 and the gas storage tank 7, and control the gas pressure of the air cavity 62 above the sealing baffle 61 in the surge tank 6, thereby reducing the gas pressure in the coolant pipe 4. Adjust to the experimental preset air pressure value until the pressure and gas volume in the coolant pipeline 4 meet the requirements; The experimental process includes the following sub-steps: Sub-step a, start the main pump 2 to make the metal gallium coolant circulate in the coolant pipeline 4; Sub-step b, when the coolant circulation is stable, start the reactor core to make the reactor work normally; The inter-experiment processing process includes the following sub-steps: Sub-step A, the gas in the coolant pipeline 4 is drawn into the air intake box by the air pump 5; Sub-step B, start the main pump 2 to promote the coolant circulation, and open the core to ensure that the temperature of the liquid metal gallium in the coolant pipeline is maintained above 40 degrees.

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