Experimental device and method for spraying supercritical carbon dioxide to liquid lead bismuth

Abstract

The invention provides an experimental device and method for spraying supercritical carbon dioxide to liquid lead and bismuth, and belongs to the field of multiphase flow experiments. The problem that no good simulation means is provided for the crevasse spraying rule at present is solved. An experimental device for spraying supercritical carbon dioxide to liquid lead bismuth comprises a visual spraying test section, an inlet end of the visual spraying test section is used for leading in liquid lead bismuth (LBE), an outlet end of the visual spraying test section and a block part are coupled and arranged in an in-reactor structure simulation tank together, and a gas outlet end of the in-reactor structure simulation tank is connected with an accommodating protection device through a valve; the outlet end of the sCO2 introduction part is communicated with the visual blowing test section through a valve and a nozzle with a replaceable length-diameter ratio, and a bypass is connected with the accommodating protection device through the valve; wherein the communication part of the nozzle and the visual discharge test section and the outlet end of the visual discharge test section are visual areas. The device is mainly used for the experiment of spraying supercritical carbon dioxide to liquid lead bismuth.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of multiphase flow experiment, and particularly relates to a supercritical carbon dioxide to liquid lead bismuth injection experiment device and method. BACKGROUND

[0002] Supercritical carbon dioxide (sCO2) to liquid lead bismuth alloy (LBE) injection accident mainly refers to the injection effect caused by the high-temperature and high-pressure sCO2 in the microchannel entering the liquid LBE on the other side due to the wall rupture of the lead bismuth and supercooling small reactor Brayton cycle heat exchanger, which will cause high pressure and multiphase heat and mass transfer effect near the break and on the lead bismuth loop side, rapidly erode the surrounding heat transfer microchannel, cause a chain effect, endanger the safety of the loop boundary containing radioactive substances, and cause a nuclear safety accident.

[0003] At present, there is no effective visual simulation means, which cannot provide technical support for the safety analysis and prevention measures of the break accident in the research and operation of the lead bismuth fast reactor and related parts. SUMMARY

[0004] Therefore, the present application aims to provide a supercritical carbon dioxide to liquid lead bismuth injection experiment device and method to solve the problem that there is no better simulation means for the break injection law.

[0005] To achieve the above-mentioned purpose, the present application adopts the following technical scheme, according to one aspect of the present application, a supercritical carbon dioxide to liquid lead bismuth injection experiment device is provided, comprising: A visual injection test section, an inlet end is used to introduce liquid LBE, an outlet end is coupled with a baffle part and is arranged in a reactor internal structure simulation tank together, a gas outlet end of the reactor internal structure simulation tank is connected with a containment protection device through a valve; A sCO2 introduction part, an outlet end is communicated with the visual injection test section through a valve, a nozzle with replaceable length-diameter ratio and a visual injection test section, and a bypass is connected with the containment protection device through a valve; The nozzle is communicated with the visual injection test section and the visual injection test section outlet end.

[0006] Further, pressure sensors and / or temperature sensors are arranged on the visual injection test section, the sCO2 introduction part and the sCO2 introduction part bypass.

[0007] Further, pressure sensors are arranged in the reactor internal structure simulation tank and the containment protection device.

[0008] Further, the baffle part is a reactor internal component or an obstacle.

[0009] Further, the sCO2 introduction part is provided with a flow meter.

[0010] Further, the sCO2 introduction part is provided with a flow meter.

[0011] Further, the sCO2 introduction part is provided with a flow meter.

[0012] Further, the sCO2 introduction part is provided with a flow meter.

[0013] Further, the sCO2 introduction part is provided with a flow meter.

[0014] According to another aspect of the present application, a method for using a supercritical carbon dioxide to a liquid lead bismuth spray experiment device is provided, comprising the following steps: Check the circuit to ensure that the valve is in the closed state; Send the liquid LBE reaching the predetermined temperature and pressure into the visualization spray test section; The liquid LBE in the visualization spray test section enters the lower part of the in-pile structure simulation tank and is kept in liquid state by the heating element, and the outlet valve of the in-pile structure simulation tank is opened to allow it to flow back to the matching device to form a circulation; Open the valve of the sCO2 introduction part bypass, and the sCO2 enters the containment protection device through the bypass, and whether the sCO2 temperature and pressure parameters meet the experimental working condition requirements is detected; After the sCO2 and the liquid LBE temperature and pressure reach the predetermined experimental working condition, the bypass valve is closed, the nozzle front valve is opened, and the spray experiment of sCO2 to the visualization spray test section lead bismuth microchannel and the in-pile structure simulation tank is started, the test process is recorded by using a high-speed camera, the phenomenon process and characteristics of the spray are observed, including the jet diffusion state and the subsequent two-phase flow state, and the related temperature, pressure, flow and phase distribution test data are collected and recorded; When the pressure in the in-pile structure simulation tank exceeds the set value, the CO2 gas is discharged to the containment protection device, and finally discharged after cooling and filtering.

[0015] Compared with the prior art, the present application has the following beneficial effects: 1. The experimental device has multiple functions and strong expandability; different nozzles can be used to simulate different break size, different temperature of lead bismuth side, different pressure and temperature of sCO2 side, and other operating condition parameter conditions; the diameter and length of the flow channel of the visualization spray test section can be adjusted according to the actual spray situation.

[0016] 2、The experimental device is visualized and accurate in measurement; the visualized spray test section is a visualized channel, if the experimental channel is too long to cause difficulty in visualized process production, segmented visualization can be used; a high-speed camera is used to directly record the experimental process and observe the phenomenon of spray; a pressure measuring point and multiple temperature and probe measuring points are arranged on the microchannel directly below the nozzle, which can accurately measure the bubble growth, pressure generation, release and superposition and other characteristics caused by stagnation effect at the break.

[0017] 3、The lead bismuth alloy can be reused; an in-pile structure simulation tank is arranged at the spray outlet of the lead bismuth channel to separate CO2 and liquid LBE after spray; the heating element wound at the bottom of the lead bismuth channel and the in-pile structure simulation tank can ensure that the LBE is always in a liquid state, and opening the valve can make the LBE flow to the related matching device, so that the lead bismuth can be recycled.

[0018] 4、The experimental device is safe and environmentally friendly; a CO2 and lead bismuth spray residue containing and protecting device is arranged, when the pressure of the in-pile structure simulation tank exceeds the set value, the pressure relief valve can be opened to discharge the CO2 gas to the containing and protecting device, and after cooling and filtering, the gas is finally discharged into the atmosphere, which has no adverse effects on the experimental personnel and the environment. BRIEF DESCRIPTION OF DRAWINGS

[0019] The drawings that form a part of this application provide further understanding of the present application, the schematic embodiments of the present application and the description thereof serve to explain the present application, and do not constitute improper limitation on the present application. In the drawings: Figure 1 A structure schematic view of a supercritical carbon dioxide to liquid lead bismuth spray experimental device according to the present application.

[0020] Flow meter 1; pressure relief valve 2; in-pile structure simulation tank 3; nozzle 4; baffle 5; containing and protecting device 6; first heating element 7; second heating element 8; first temperature measuring point cluster 9; second temperature measuring point cluster 10; first visualized area 11; second visualized area 12; visualized spray test section 13; sCO2 introduction part 14. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict, and the described embodiments are only part of the embodiments of the present application, but not all the embodiments.

[0022] It should be noted that the present application is described with respect to "left", "right", "left side", "right side", "upper", "lower", "top", "bottom" and the like, which are defined based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the described structure must be constructed and operated in a particular orientation, therefore, it cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0023] In the description of the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0024] According to one aspect of the present application, a supercritical carbon dioxide to liquid lead bismuth spray experiment device is provided, comprising: The visualized sparging test section 13 has an inlet end for introducing liquid LBE and an outlet end coupled with the baffle 5 and disposed in the in-vessel structure simulation tank 3 together, and the gas outlet end of the in-vessel structure simulation tank 3 is connected with the containment protection device 6 through a valve; the visualized sparging test section 13 is a transparent pipeline as a whole, which can provide a prerequisite for a visualized measurement process, and can observe the phenomenon process of sparging in cooperation with a high-speed camera, and the visualized length of the visualized sparging test section 13 can be displayed according to actual process requirements, and the visualized sparging test section 13 can be made into a completely transparent whole or a segmented transparent mode, and a reasonable selection can be made according to actual needs. The baffle 5 is specifically provided as an in-vessel component or an obstacle. Temperature measuring points are installed on the baffle and the space in front of the baffle to measure relevant parameters of sCO2 after being injected into the in-vessel structure together with lead-bismuth after sparging. The gas outlet end of the in-vessel structure simulation tank 3 is connected with the containment protection device 6 through a valve, which can form feedback by detecting the pressure of the containment protection device 6 before the experiment, judge whether the pressure of sCO2 reaches a preset pressure value, and thus ensure that the experiment process can enable sCO2 of a predetermined pressure flow rate to participate in the experiment. During the experiment process, if the pressure abnormally rises, the gas with excessively high pressure can enter the containment protection device 6 to be collected and effectively cooled, and after the experiment is completed, the gas with a higher temperature can be collected through the containment protection device 6 due to the stratification of the gas and the liquid, and the gas can be discharged after being cooled, so as to ensure environmental protection and safety. The diameter of the visualized sparging test section 13 can be determined according to the channel size of the printed circuit board heat exchanger and the tubular heat exchanger, and the length can be adjusted according to requirements and actual sparging conditions, and there is a row of temperature measuring points and probe measuring points above and below the channel, and the spacing can be changed. The visualized channel is externally wrapped with a heating and heat preservation device to prevent the normally flowing liquid lead-bismuth from solidifying.

[0025] The sCO2 introduction part 14 has an outlet end communicated with the visualized sparging test section 13 through a valve and a nozzle 4 with a replaceable length-diameter ratio, and a bypass communicated with the containment protection device 6 through a valve; the sCO2 introduction part 14 is also provided as a pipeline for introducing sCO2 with a predetermined pressure and flow rate. Specifically, a flowmeter 1 is arranged in the sCO2 introduction part 14 pipeline to feedback the flow of sCO2. The nozzle 4 with different length-diameter ratios is fixed on the lead-bismuth channel of the experimental section in a detachable connection mode through a nozzle outer screw with a fixed diameter.

[0026] The communication position of the nozzle 4 and the visualized sparging test section 13 is a first visualized area 11, and the outlet end of the visualized sparging test section 13 is a second visualized area 12. The visualized area is provided for observing the experimental process. This setting mode is a minimum visualized area limitation, which can ensure the visuality of the entire flow path under the allowable conditions, and can better observe the entire process.

[0027] In the embodiment, pressure sensors and / or temperature sensors are arranged on the visualized blowdown test section 13, the sCO2 introduction part 14, and the sCO2 introduction part 14 bypass. The pressure and temperature in the feedback flow path can be detected in real time, and adjustment is made according to predetermined experimental conditions and blowdown pressure, forming a feedback adjustment mechanism, ensuring parameterization and feedback of the entire process, and providing data support for research. The sCO2 after blowdown is injected into the in-pile structure simulation tank 3 together with lead bismuth, and the pressure in the in-pile structure simulation tank 3 is consistent with the pressure on the lead bismuth side.

[0028] In the embodiment, pressure sensors are arranged in the in-pile structure simulation tank 3 and the containment protection device 6. The purpose is to prevent the pressure in the in-pile structure simulation tank 3 from being too high and causing danger, and the pressure detection of the containment protection device 6 can provide correction feedback for the pressure and flow rate of sCO2 in the initial stage, ensuring that the predetermined experimental requirements are met; at the same time, the pressure can be detected when CO2 is collected, and when a certain safety warning is reached, the pressure can be actively fed back to control the valve to discharge the pressure, ensuring the safety of the entire experimental process.

[0029] In the embodiment, temperature measurement points are arranged at the communication part of the sCO2 introduction part 14 and the visualized blowdown test section 13 and the outlet end of the visualized blowdown test section 13. Specifically, the communication part of the sCO2 introduction part 14 and the visualized blowdown test section 13 is the first temperature measurement point cluster 9, and the outlet end of the visualized blowdown test section 13 is the second temperature measurement point cluster area 10. A certain number of uniformly arranged temperature sensors are arranged in each temperature measurement point cluster area to collect temperature change data.

[0030] In the embodiment, a plurality of probe measurement points are arranged in the visualized blowdown test section 13 in a certain regular pattern for simultaneous sCO2 and LBE phase distribution measurement and temperature measurement. The growth of bubbles, pressure generation, release, and superposition caused by stagnation effect at the break can be accurately measured.

[0031] In the embodiment, the sCO2 introduction part 14 is coupled with a heating element at the communication position with the visualized jet test section 13 and on the in-core structure simulation tank 3. The second heating element 8 is wound on the outer wall of the in-core structure simulation tank 3, for continuously heating the liquid LBE to ensure that the liquid LBE is in liquid state. In combination with the loop formed by the liquid outlet end of the in-core structure simulation tank 3 and the inlet end of the visualized jet test section 13, the liquid LBE can be drained back to be reused under certain conditions. The first heating element 7 is wound at the communication position of the sCO2 introduction part 14 with the visualized jet test section 13, to ensure the temperature of the liquid LBE when meeting the sCO2 during the experiment, so that the experiment is carried out according to the preset conditions. The feedback of the temperature sensor is controlled to realize accurate data. The heating form and appearance of the first heating element 7 and the second heating element 8 are reasonably selected according to the required temperature and the shape and position of the fixed position.

[0032] In the above description, the valve is set as a pressure relief valve 2 as needed.

[0033] According to another aspect of the present application, a method for using a supercritical carbon dioxide to a liquid lead bismuth jet test device as described above is provided, comprising the following steps: Check the circuit to ensure that the valves are in the closed state; Send the liquid LBE reaching the predetermined temperature and pressure into the visualized jet test section 13; The liquid LBE in the visualized jet test section 13 enters the lower part of the in-core structure simulation tank 3 and is kept in liquid state by the heating element, which is a heating wire wound on the bottom of the in-core structure simulation tank 3. The outlet end valve of the in-core structure simulation tank 3 is opened so that it can flow back to the matching device to form a circulation; Open the valve of the sCO2 introduction part 14 bypass, and the sCO2 enters the containment protection device 6 through the bypass, and detects whether the sCO2 temperature and pressure parameters meet the experimental working condition requirements; After the sCO2 and the liquid LBE temperature and pressure reach the predetermined test working condition, the bypass valve is closed, the nozzle 4 front valve is opened, and the sCO2 jet test in the visualized jet test section lead bismuth microchannel and the in-core structure simulation tank is started. The high-speed camera is used to record the test process, and the jet phenomenon process and characteristics are observed, including the jet diffusion state and the subsequent two-phase flow state. The relevant temperature, pressure, flow and phase distribution test data are collected and recorded; When the pressure in the in-pile structure simulation tank 3 exceeds the set value, the CO2 gas is discharged to the storage protection device 6 and finally discharged after being cooled and filtered. After the spray, the CO2 gas and the lead bismuth are layered in the in-pile structure simulation tank 3, the lead bismuth is gathered at the bottom, and is kept in liquid state by heating through the heating wire wound at the bottom, so as to flow to the matched device, so as to achieve the effect of LBE recycling. The CO2 is gathered in the upper space, and when the pressure in the tank exceeds the set value, the pressure relief valve is opened to discharge the CO2 gas to the CO2 and lead bismuth spray residue storage protection device 6, and finally discharged into the atmosphere after being cooled and filtered.

[0034] In the above description, the sensors, controllers and control programs that can be involved are all prior art and are not described in detail.

[0035] The above disclosed embodiments of the present application are only used to help explain the present application. The embodiments do not describe all the details, nor limit the present application to the specific embodiments described. According to the content of the present application, many modifications and changes can be made. The present application selects and specifically describes these embodiments in order to better explain the principles and practical applications of the present application, so that those skilled in the art can well understand and utilize the present application.

Claims

1. An experimental apparatus for injecting supercritical carbon dioxide into liquid lead-bismuth, characterized in that, include: The visual discharge test section (13) has an inlet end for introducing liquid LBE and an outlet end coupled with the baffle (5) and set together in the in-pile structure simulation tank (3). The gas outlet end of the in-pile structure simulation tank (3) is connected to the containment protection device (6) via a valve. The CO2 inlet (14) is connected to the visual discharge test section (13) via a valve and a length-to-diameter replaceable nozzle (4) at the outlet end, and the bypass is connected to the containment protection device (6) via a valve. The visible area is the connection point between the nozzle (4) and the visual discharge test section (13) and the outlet end of the visual discharge test section (13).

2. The experimental apparatus for supercritical carbon dioxide injection into liquid lead-bismuth according to claim 1, characterized in that: Pressure sensors and / or temperature sensors are installed on the visual discharge test section (13), the sCO2 inlet (14), and the bypass of the sCO2 inlet (14).

3. The experimental apparatus for injecting supercritical carbon dioxide into liquid lead-bismuth according to claim 2, characterized in that: Pressure sensors are installed in both the in-pile structure simulation tank (3) and the containment protection device (6).

4. The experimental apparatus for supercritical carbon dioxide injection into liquid lead-bismuth according to claim 1, characterized in that: The blocking part (5) is an internal component or obstacle.

5. An experimental apparatus for releasing supercritical carbon dioxide into liquid lead-bismuth according to claim 1, 2, 3 or 4, characterized in that: A flow meter (1) is installed inside the CO2 inlet (14).

6. The experimental apparatus for injecting supercritical carbon dioxide into liquid lead-bismuth according to claim 5, characterized in that: Temperature measurement points are set at the connection between the CO2 inlet (14) and the visual discharge test section (13) and at the outlet of the visual discharge test section (13).

7. The experimental apparatus for supercritical carbon dioxide injection into liquid lead-bismuth according to claim 6, characterized in that: The visualization discharge test section (13) is equipped with several probe measurement points distributed in a certain pattern, which are used to simultaneously measure the phase distribution of sCO2 and LBE and the temperature.

8. The experimental apparatus for supercritical carbon dioxide injection into liquid lead-bismuth according to claim 1, characterized in that: The liquid outlet end of the in-pile structure simulation tank (3) and the inlet end of the visualization spray test section (13) form a loop.

9. The experimental apparatus for supercritical carbon dioxide injection into liquid lead-bismuth according to claim 1, characterized in that: Heating elements are coupled to the connection between the sCO2 inlet (14) and the visualization spray test section (13) and to the in-pile structure simulation tank (3).

10. A method for using a supercritical carbon dioxide injection experimental apparatus for liquid lead-bismuth as described in claims 1, 2, 3, 4, 6, 7, 8, or 9, characterized in that, Includes the following steps: Check the circuit and ensure that all valves are closed. The liquid LBE that has reached the predetermined temperature and pressure is sent into the visual discharge test section (13). The liquid LBE in the visual discharge test section (13) enters the lower part of the in-pile structure simulation tank (3) and is kept in liquid state by the heating element. The valve at the outlet end of the in-pile structure simulation tank (3) is opened so that it can flow back to the supporting device to form a cycle. Open the valve of the bypass of the sCO2 inlet (14), and the sCO2 enters the containment protection device (6) through the bypass, and check whether the temperature and pressure parameters of the sCO2 meet the experimental conditions. After the temperature and pressure of sCO2 and liquid LBE reach the predetermined test conditions, close the bypass valve, open the valve before the nozzle (4), and start the sCO2 injection experiment into the lead-bismuth microchannel and the in-pile structure simulation tank of the visualization injection test section. Use a high-speed camera to record the test process, observe the injection phenomenon process and characteristics, including the jet diffusion state and the subsequent two-phase flow state, and collect and record relevant temperature, pressure flow rate and phase distribution test data. When the pressure inside the in-pile structure simulation tank (3) exceeds the set value, CO2 gas is discharged to the containment protection device (6), and finally discharged after cooling and filtration.

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