阅读说明：本技术 一种铅铋快堆非能动应急余热排出系统实验装置及方法 (Experimental device and method for passive emergency waste heat removal system of lead-bismuth fast reactor ) 是由 张魁 商宝娟 吴志远 田文喜 苏光辉 秋穗正 于 2021-08-16 设计创作，主要内容包括：一种铅铋快堆非能动应急余热排出系统实验装置及方法,该实验装置包括冷凝系统、补水系统、预热段、加热系统、氮气供应系统、流量测量系统、去离子水补水系统、主蒸汽管线电动截止阀和回流管线电动截止阀。冷凝系统用于将高温蒸汽冷凝成单相水,为自然循环提供冷源；补水系统用于非能动应急余热排出系统投运后,向单根螺旋管二次侧注水以带走堆芯衰变热,保证非能动余热排出系统的正常运行；预热段用于加热冷凝系统流出的单相水,使流入单根螺旋管的水达到符合要求的压力和温度；加热系统用于将单相水加热成单相蒸汽,带走堆芯衰变热,为自然循环提供热源。本发明可用于开展应急余热排出系统启动与稳态运行自然循环流动换热特性实验研究。(An experimental device and method for a passive emergency waste heat discharge system of a lead-bismuth fast reactor are disclosed. The condensing system is used for condensing the high-temperature steam into single-phase water to provide a cold source for natural circulation; the water supplementing system is used for injecting water to the secondary side of the single spiral pipe to take away decay heat of the reactor core after the passive emergency waste heat discharging system is put into operation, so that the normal operation of the passive waste heat discharging system is ensured; the preheating section is used for heating single-phase water flowing out of the condensing system, so that the water flowing into the single spiral pipe reaches the pressure and the temperature meeting the requirements; the heating system is used for heating single-phase water into single-phase steam, takes away decay heat of the reactor core and provides a heat source for natural circulation. The invention can be used for developing the experimental study on the starting and steady-state operation natural circulation flow heat exchange characteristics of the emergency waste heat discharge system.)

1. The utility model provides an active emergent waste heat discharge system experimental apparatus of lead bismuth fast reactor non which characterized in that: the system is composed of a condensing system, a water supplementing system, a preheating section (1), a heating system, a nitrogen supply system, a flow measuring system, a deionized water supplementing system, a main steam pipeline electric stop valve (5) and a return pipeline electric stop valve (11); the condensing system is composed of a condensing water tank (6) and a condenser (7), a plurality of electric heating rods (8) are arranged in the condensing water tank (6), the condenser (7) is arranged in the condensing water tank (6), and a discharge valve (20) is connected with the condensing water tank (6) and used for adjusting the pressure of the condensing water tank (6); a reflux pipeline electric stop valve (11) is arranged on a reflux pipeline of the condenser (7) connected with the preheating section (1); the heating system adopts a single spiral pipe (4) to simulate a lead-bismuth fast reactor direct current steam generator, and fluid flows from bottom to top in the single spiral pipe; the pipeline connected between the outlet of the single spiral pipe (4) and the inlet of the condenser (7) is a main steam pipeline; a pipeline connected between the outlet of the condenser (7) and the inlet of the single spiral pipe (4) is a return pipeline; a main steam pipeline electric stop valve (5) is arranged between the single spiral pipe (4) and the condenser (7); a check valve (2) is connected between the preheating section (1) and the heating system to prevent backflow; the discharge valve (3) is used for emptying all water in the experiment loop; the water replenishing system comprises a starting water replenishing tank (14) and a safety valve (15) arranged on the starting water replenishing tank (14), wherein a pipeline connected between the starting water replenishing tank (14) and a nitrogen cylinder (13) is a nitrogen interface pipeline, the starting water replenishing tank (14) is connected with a pipeline between a main steam pipeline electric stop valve (5) and a condenser (7) through a main steam inlet pipeline, and the starting water replenishing tank (14) is connected with a pipeline between a check valve (10) and a backflow pipeline electric stop valve (11) through a backflow pipeline; the nitrogen supply system consists of a first valve (V1) with a nitrogen bottle (13) connected with the heating system, a second valve (V2) with the nitrogen bottle (13) connected with a main steam pipeline, a third valve (V3) with the nitrogen bottle (13) connected with a starting water replenishing tank (14) and the nitrogen bottle (13); the flow measuring system is composed of a first flow measuring meter (9), a second flow measuring meter (12) and a third flow measuring meter (21), wherein the first flow measuring meter (9) is arranged between a condenser (7) and a check valve (10), the second flow measuring meter (12) is arranged between a backflow pipeline electric stop valve (11) and the preheating section (1), the third flow measuring meter (21) is arranged on a backflow pipeline of a starting water replenishing tank (14), and the check valve (10) is connected between the first flow measuring meter (9) and the second flow measuring meter (12) to prevent backflow; the deionized water replenishing system consists of a centrifugal pump (18) and a deionized water tank (19) which are connected; the deionized water charging system is connected with the water charging system through a first stop valve (16) and is connected with the condensing system through a second stop valve (17).

2. The experimental device of the passive emergency waste heat removal system of the lead-bismuth fast reactor according to claim 1, characterized in that: the water temperature in the condensate water tank (6) is ensured to be stable by adjusting the working frequency of the centrifugal pump (18), the power of an electric heating rod (8) in the condensate water tank (6) and the opening of the discharge valve (20); the starting water replenishing tank (14) is designed to have the height-diameter ratio of 1.83, and pressure fluctuation in the working process is reduced.

3. The experimental device of the passive emergency waste heat removal system of the lead-bismuth fast reactor according to claim 1, characterized in that: the height of the condensing system is higher than that of the heating system, and the height difference exists, so that the natural circulation characteristic of the prototype system can be truly reflected.

4. The experimental device of the passive emergency waste heat removal system of the lead-bismuth fast reactor according to claim 1, characterized in that: the preheating section (1) and the single spiral pipe (4) are wrapped with aluminum silicate fiber felt so as to effectively preserve heat.

5. The experimental device of the passive emergency waste heat removal system of the lead-bismuth fast reactor according to claim 1, characterized in that: the heat exchange tube of the condenser (7) is in a snake shape and can bear the steam pressure of 13 MPa.

6. The experimental method of the experimental device of the passive emergency residual heat removal system of the lead-bismuth fast reactor according to any one of claims 1 to 5, characterized in that: when the experiment starts, the relief valve (3) is opened to drain water in the loop, so that the influence on the flow of the loop is eliminated, and the experiment precision is improved;

opening a second valve (V2), and filling a pipeline between the main steam pipeline electric stop valve (5) and the check valve (10) at the outlet of the condenser (7) with gauge pressure nitrogen by adjusting the opening degree of the second valve (V2); adjusting the opening degree of a third valve (V3) to increase the pressure of the starting water replenishing tank (14) and the return line to a required value; the first valve (V1) is opened, the opening degree of the first valve (V1) is adjusted to enable the pressure in the single spiral pipe (4) to be stabilized at a required value, and the influence of the system pressure on an experimental result is reduced; in the adjusting process, the heating power of the preheating section (1) is adjusted, the water temperature at the inlet of the single spiral pipe (4) is adjusted, the working frequency of a centrifugal pump (18) of a deionized water replenishing system, the power of an electric heating rod (8) of a condensed water tank (6) and the opening degree of a discharge valve (20) are adjusted, and the water temperature in the condensed water tank (6) is guaranteed to be stable; after the experiment is completed, the bottom relief valve (3) of the loop is opened, liquid in the single spiral pipe (4) is emptied, the first valve (V1) is opened, and the heating system is filled with gauge pressure nitrogen, namely nitrogen filling protection is carried out.

Technical Field

The invention relates to the technical field of passive emergency waste heat discharge systems, in particular to an experimental device and method for a lead-bismuth fast reactor passive emergency waste heat discharge system.

Background

After the fukushima nuclear accident, a secondary side passive emergency residual heat removal (ECS) system is widely adopted in a second-generation and third-generation megawatt pressurized water reactor to meet the requirement of reactor core decay heat derivation in super-design benchmark accidents such as full-field power failure. The ECS system is based on a steam generator secondary side closed natural circulation basic principle, steam generated by the steam generator secondary side is condensed in the heat exchanger to become single-phase water and then returns to the steam generator secondary side, decay heat generated by the primary loop reactor core is transferred to water in the heat exchange water tank by the heat exchanger, the reactor core decay heat can be derived without an external power supply, and the reasonability of related design needs to be verified before the new design system is put into engineering application. The scholars at home and abroad carry out extensive experiments and theoretical researches on stack-type passive emergency waste heat discharge systems such as AC600, CPR1000, Hualongyi and the like, and find that the starting and operating characteristics of the ECS system are greatly changed under different working conditions because the driving pressure head of natural circulation is relatively small. At present, the research on the flow heat exchange characteristic of the lead-bismuth fast reactor emergency waste heat discharge system in the starting and running processes is still in the initial exploration stage at home and abroad.

Disclosure of Invention

The invention aims to provide an experimental device and an experimental method for a lead-bismuth fast reactor passive emergency waste heat removal system, and provides the experimental device and the experimental method for researching the flow heat exchange characteristics of the passive emergency waste heat removal system in the starting and running processes.

In order to achieve the purpose, the invention adopts the following technical scheme:

an experimental device for a lead-bismuth fast reactor passive emergency waste heat discharge system comprises a condensation system, a water supplementing system, a preheating section 1, a heating system, a nitrogen supply system, a flow measuring system, a deionized water supplementing system, a main steam pipeline electric stop valve 5 and a return pipeline electric stop valve 11; the condensing system consists of a condensing water tank 6 and a condenser 7, wherein a plurality of electric heating rods 8 are arranged in the condensing water tank 6, the condenser 7 is arranged in the condensing water tank 6, and a discharge valve 20 is connected with the condensing water tank 6 and used for adjusting the pressure of the condensing water tank 6; a reflux pipeline electric stop valve 11 is arranged on a reflux pipeline of the condenser 7 connected with the preheating section 1; the heating system adopts a single spiral pipe 4 to simulate a lead-bismuth fast reactor direct-current steam generator, and fluid flows from bottom to top in the single spiral pipe; the pipeline connected between the outlet of the single spiral pipe 4 and the inlet of the condenser 7 is a main steam pipeline; the pipeline connected between the outlet of the condenser 7 and the inlet of the single spiral pipe 4 is a return pipeline; a main steam pipeline electric stop valve 5 is arranged between the single spiral pipe 4 and the condenser 7; a check valve 2 is connected between the preheating section 1 and the heating system to prevent backflow; the discharge valve 3 is used for emptying all water in the experiment loop; the water supplementing system consists of a starting water supplementing tank 14 and a safety valve 15 arranged on the starting water supplementing tank 14, wherein a pipeline connected between the starting water supplementing tank 14 and a nitrogen cylinder 13 is a nitrogen interface pipeline, the starting water supplementing tank 14 is connected with a pipeline between the main steam pipeline electric stop valve 5 and the condenser 7 through a main steam inlet pipeline, and the starting water supplementing tank 14 is connected with a pipeline between the check valve 10 and the backflow pipeline electric stop valve 11 through a backflow pipeline; the nitrogen supply system consists of a first valve V1 connected with the heating system through a nitrogen bottle 13, a second valve V2 connected with the main steam pipeline through the nitrogen bottle 13, a third valve V3 connected with the starting water replenishing tank 14 through the nitrogen bottle 13 and the nitrogen bottle 13; the flow measuring system consists of a first flow meter 9, a second flow meter 12 and a third flow meter 21, wherein the first flow meter 9 is arranged between the condenser 7 and the check valve 10, the second flow meter 12 is arranged between the electric stop valve 11 of the return pipeline and the preheating section 1, the third flow meter 21 is arranged on a return pipeline of the starting water replenishing tank 14, and the check valve 10 is connected between the first flow meter 9 and the second flow meter 12 to prevent backflow; the deionized water replenishing system consists of a centrifugal pump 18 and a deionized water tank 19 which are connected; the deionized water charging system is connected with the water charging system through a first stop valve 16 and is connected with the condensing system through a second stop valve 17.

The preheating section adopts low-voltage heavy-current alternating current to directly heat through the resistance of the steel pipe, continuously adjusts voltage through the autotransformer, changes electric heating power (electric power can be continuously adjusted), becomes low-voltage heavy current through the heavy-current transformer, directly inserts the electric heating section with copper braid and copper plate to adjust single spiral pipe inlet fluid temperature, realize multiunit variable working condition experiment.

The stable water temperature in the condensate water tank 6 is ensured by adjusting the working frequency of the centrifugal pump 18, the power of the electric heating rod 8 in the condensate water tank 6 and the opening degree of the discharge valve 20; the start-up make-up tank 14 is designed to have an aspect ratio of 1.83, which helps to reduce pressure fluctuations during operation.

The height of the condensing system is higher than that of the heating system, and the height difference exists, so that the natural circulation characteristic of the prototype system can be truly reflected.

The preheating section 1 and the single spiral tube 4 are wrapped with an aluminum silicate fiber felt so as to effectively insulate them.

The heat exchange tube of the condenser 7 is in a snake shape and can bear the steam pressure of 13 MPa.

The experimental method of the experimental device of the lead bismuth fast reactor passive emergency residual heat removal system,

when the experiment starts, the relief valve 3 is opened to drain water in the loop, so that the influence on the flow of the loop is eliminated, and the experiment precision is improved;

opening a second valve V2, and filling a pipeline between the main steam pipeline electric stop valve 5 and the check valve 10 at the outlet of the condenser 7 with gauge pressure nitrogen by adjusting the opening degree of the second valve V2; adjusting the opening degree of the third valve V3 to increase the pressure of the starting water replenishing tank 14 and the return line to a required value; the first valve V1 is opened, the opening degree of the first valve V1 is adjusted to enable the pressure in the single spiral pipe 4 to be stabilized at a required value, and the influence of the system pressure on an experimental result is reduced; in the adjusting process, the heating power of the preheating section 1 is adjusted, the water temperature at the inlet of the single spiral pipe 4 is adjusted, the working frequency of a centrifugal pump 18 of a deionized water supplementing system, the power of an electric heating rod 8 of a condensed water tank 6 and the opening degree of a discharge valve 20 are adjusted, and the stability of the water temperature in the condensed water tank 6 is ensured; after the experiment is completed, the bottom relief valve 3 of the loop is opened, liquid in the single spiral pipe 4 is emptied, the first valve V1 is opened, and the heating system is filled with gauge pressure nitrogen, namely nitrogen filling protection is carried out.

Compared with the prior art, the invention has the following advantages:

1) the preheating section can effectively control and adjust the inlet temperature of the heating system, so that the flowing heat exchange characteristic of the passive emergency waste heat discharge system in the starting and running processes can be researched;

2) the deionized water replenishing system adopts a centrifugal pump, and the condensate water tank is provided with an electric heating rod and a discharge valve, so that the temperature of water in the condensate water tank can be ensured to be stable, and the experimental precision can be ensured;

3) the steam pipeline valve and the return pipeline valve adopt electric stop valves, have a linear opening function of 5-30.0s, and have adjustable opening time, so that the opening and closing operation of the valves is reliably ensured.

Drawings

FIG. 1 is a schematic diagram of an experimental device of a passive emergency waste heat removal system of a lead-bismuth fast reactor.

Detailed Description

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

As shown in attached figure 1, the experimental device for the passive emergency waste heat discharge system of the lead-bismuth fast reactor comprises a condensation system, a water charging system, a preheating section 1, a heating system, a nitrogen supply system, a flow measurement system, a deionized water charging system, a main steam pipeline electric stop valve 5 and a return pipeline electric stop valve 11; the condensing system is used for condensing the high-temperature steam into single-phase water, providing a cold source for natural circulation, and leading out the decay heat of the reactor core without an external power supply; the water supplementing system is used for injecting water to the secondary side of the single spiral pipe to take away decay heat of the reactor core after the passive emergency waste heat discharging system is put into operation, so that the normal operation of the passive waste heat discharging system is ensured; the preheating section is used for heating single-phase water flowing out of the condensing system, so that the water flowing into the single spiral pipe reaches the pressure and the temperature meeting the requirements; the heating system is used for heating single-phase water into single-phase steam, takes away decay heat of the reactor core and provides a heat source for natural circulation. Flow measurement systems are used for flow in a circuit. The experimental device can be used for carrying out experimental research on the starting and steady-state operation natural circulation flow heat exchange characteristics of the emergency waste heat discharge system.

The condensation system main body is an open cube and consists of a condensation water tank 6 and a condenser 7, the condenser 7 is mainly formed by welding and connecting a straight pipe and a part of bent pipes and is made of 304 stainless steel, the condenser 7 is arranged in the condensation water tank 6, the condensation water tank 6 is made of 304 stainless steel and is formed by welding 5 stainless steel plates, and 8 electric heating rods 8 are arranged in the condensation water tank 6 to maintain the pressure and the temperature in the condensation water tank 6; the preheating section 1 is a snakelike preheating section designed near the inlet of a single spiral pipe, controls the fluid temperature, and consists of an inner layer and an outer layer, wherein the innermost layer is made of stainless steel, the outer layer is made of aluminum silicate heat-insulating cotton, and the outermost layer is made of a coating material; a reflux pipeline electric stop valve 11 is arranged on a reflux pipeline of the condenser 7 connected with the preheating section 1; the heating system comprises a single spiral pipe 4, a flange is welded at the inlet and the outlet of the single spiral pipe 4 respectively and is used for being fixedly connected with two flanges on a main pipeline of the experiment table frame, and an insulating gasket is adopted between the connected flanges. The inlet and outlet straight pipes of the single spiral pipe 4 respectively clamp a red copper plate electrode, the copper plate electrodes are connected with the positive electrode and the negative electrode of a direct current power supply by adopting braided copper braids and are connected by silver brazing; the pipeline connected between the outlet of the single spiral pipe 4 and the inlet of the condenser 7 is a main steam pipeline; the pipeline connected between the outlet of the condenser 7 and the inlet of the single spiral pipe 4 is a return pipeline; a main steam pipeline electric stop valve 5 is arranged between the single spiral pipe 4 and the condenser 7; the water replenishing system main body is a starting water replenishing tank 14, the starting water replenishing tank 14 is cylindrical and made of 304 stainless steel, a safety valve 15 is arranged at the top of the starting water replenishing tank, a pipeline connected between the starting water replenishing tank 14 and a nitrogen cylinder 13 is a nitrogen interface pipeline, the starting water replenishing tank 14 is connected with a pipeline between a main steam pipeline electric stop valve 5 and a condenser 7 through a main steam inlet pipeline, and a starting water replenishing tank 114 is connected with a pipeline between a check valve 10 and a backflow pipeline electric stop valve 11 through a backflow removing pipeline; the nitrogen supply system consists of a valve V1 connected with the heating system through a nitrogen bottle 13, a valve V2 connected with the main steam pipeline through the nitrogen bottle 13, a valve V3 connected with the starting water replenishing tank through the nitrogen bottle 13 and the starting water replenishing tank, and the nitrogen bottle 13, and realizes pressure control and protection of the loop through adjusting the opening degree of the valve. The flow measuring system consists of a first flow meter 9, a second flow meter 12 and a third flow meter 21, wherein the first flow meter 9 is arranged between the condenser 7 and the check valve 10, the second flow meter 12 is arranged between the electric stop valve 11 of the return pipeline and the preheating section 1, the third flow meter 21 is arranged on a return pipeline of the starting water replenishing tank 14, and the check valve 10 is connected between the first flow meter 9 and the second flow meter 12 to prevent backflow; the deionized water charging system is composed of a centrifugal pump 18 and a deionized water tank 19, is connected with the water charging system through a first stop valve 16, is communicated with the condensation system through a second stop valve 17, and adjusts the working frequency of the centrifugal pump 18, the power of an electric heating rod 8 of the condensed water tank 6 and the opening degree of a discharge valve 20, so that the water temperature in the condensed water tank 6 is stable.

As the preferred embodiment of the invention, the main steam pipeline electric stop valve 5 and the return pipeline electric stop valve 11 have the linear opening function of 5-30.0s, and the opening time is adjustable, so that the opening and closing operation of the valves is reliably ensured, and the influence of water hammer on the experimental result is eliminated.

As the preferred embodiment of the invention, the electric heating power of the preheating section can be continuously adjusted, the inlet temperature of a heating system can be controlled, and the experimental precision is improved.

As shown in fig. 1, in the experimental method of the experimental device for the passive emergency waste heat removal system of the lead-bismuth fast reactor, the relief valve 3 is opened, and all water in the experimental loop is drained; opening a second valve V2, and adjusting the opening of the valve to fill gauge pressure nitrogen in a pipeline between the electric stop valve 5 of the main steam pipeline and the check valve 10 at the outlet of the condenser 7; adjusting the opening degree of a third valve V3 to increase the pressure of the starting water replenishing tank 14 and the return line to 11 MPa; the opening degree of the first valve V1 is adjusted to ensure that the pressure in the single spiral pipe 4 is stabilized at 11 MPa; switching on a power supply of the experimental section of the single spiral pipe 4, adjusting the input power of a direct current power supply, and observing the change of parameters such as pressure, temperature and the like of an inlet and an outlet of the single spiral pipe 4; linearly opening the electric stop valve 5 of the main steam pipeline at the outlet of the single spiral pipe 4 for 20s, and observing whether the outlet pressure of the condenser 7 reaches a specified value or not; after the valve is completely opened for 10s and the check valve 10 at the outlet of the condenser 7 is opened, the electric stop valve 11 of the backflow pipeline is linearly opened for 20s, so that water in the water replenishing tank 14 is started to flow into the single spiral pipe 4, and the change of parameters such as experimental loop pressure, flow, temperature, differential pressure and the like in the starting stage of the emergency waste heat discharge system is observed and recorded; after the system stably runs, observing and recording the changes of parameters such as pressure, flow, temperature, differential pressure and the like of an experimental loop in the starting stage of the emergency waste heat discharge system; in the adjusting process, the water temperature at the inlet of the single spiral pipe 4 can be adjusted by combining the adjustment of the power of the preheating section 1; in the adjusting process, the working frequency of the centrifugal pump 18 of the deionized water replenishing system, the power of the electric heating rod 8 of the condensate water tank 6 and the opening degree of the discharge valve 20 are also required to be adjusted, so that the temperature of water in the condensate water tank 6 is ensured to be stable; after the experiment is finished, the discharge valve 3 at the bottom of the loop is opened, liquid in the experiment section of the heating system is emptied, the first valve V1 is opened, and the heating system is filled with gauge pressure nitrogen, namely nitrogen filling protection is carried out.