Device and method for analyzing heat extraction system outside container for exporting waste heat from liquid metal reactor

Abstract

The invention relates to a device and a method for analyzing a heat extraction system outside a container for exporting waste heat from a liquid metal reactor, the device comprises a test body and a measuring point bracket, and the measuring point bracket is positioned in the test body; supercooled water or cold air is injected into an outer flow channel of a reaction container or an outer flow channel of a safety container filled with the liquid metal alloy pool, so that the liquid metal alloy pool simulating decay waste heat is subjected to container outer heat removal cooling; a cooling working medium is injected into a reactor pit, and the auxiliary enhancement effect of an immersion liquid metal alloy pool on heat discharge outside a container is researched; a cooling working medium is injected into the upper area of the outer flow channel of the reaction container or the outer flow channel of the safety container, and the enhancement effect of cooling of the upper liquid metal alloy on the natural circulation capacity of the liquid metal alloy pool is judged and enhanced. The device can fully consider and research different influences of test design of multiple factors such as different cooling working media, cooling flow channels, injection strength, immersion heat release, liquid metal alloy pool natural circulation capability promotion and the like on test results.

Description

Technical Field

[0001] This invention relates to the field of severe accidents in liquid metal reactors, specifically to an analysis device and method for an external heat exhaust system for removing residual heat from a liquid metal reactor. Background Technology

[0002] Liquid metal reactors (LMWRs) are one of the main directions of fourth-generation nuclear power technology development, possessing inherent advantages such as high safety and fuel proliferation. To improve the economy and compactness of LWRs, they adopt an integrated pool layout, where the primary loop liquid metal alloy pool, steam generator, forced circulation main pump, and other components are integrated within a compact reactor vessel. This design means that accident response equipment cannot be housed within the integrated reactor vessel, and residual core heat after an accident is difficult to remove directly through the liquid metal alloy pool. To address these challenges, an external heat exhaust system needs to be installed outside the reactor vessel to remove heat from the liquid metal alloy pool and the continuous decay heat of the reactor core through convective and radiative heat transfer. Therefore, the external heat exhaust system is also a crucial safety feature of LWRs.

[0003] The existing design concept for external heat exhaust systems in liquid metal reactor containers involves heating the cooling medium as it flows over the bottom of the container's outer surface. The medium then flows upwards through the system's channels via natural circulation, remaining continuously heated, and finally exits through a chimney at the top of the system. The design of external heat exhaust systems can be categorized by the cooling medium and its operating principle: using supercooled water for evaporation or cold air for buoyancy; by the object being cooled: cooling the reaction vessel or safety vessel of the liquid metal reactor; by the cooling process: initial cooling medium flow heat transfer and subsequent cooling medium immersion heat conduction; and by whether natural circulation within the liquid metal alloy pool is driven. Existing test benches for external heat exhaust systems are all scaled-down experiments designed for specific liquid metal reactor types, failing to comprehensively evaluate the heat release capacity of various design schemes and lacking mechanistic experimental research on the heat release capacity of different design schemes through natural circulation. Summary of the Invention

[0004] The purpose of this invention is to provide an analytical device and method for a container external heat dissipation system for liquid metal stacks to remove residual heat. This involves injecting supercooled water or cold air into the external flow channel of a reaction vessel or safety vessel containing a liquid metal alloy pool to cool the pool, simulating decay residual heat. The invention also investigates the auxiliary enhancement effect of immersing the liquid metal alloy pool on external heat dissipation by injecting a cooling medium into the stack pit. Furthermore, it assesses the effect of enhanced cooling of the upper liquid metal alloy pool on its natural circulation capacity by injecting a cooling medium into the upper region of the external flow channel of the reaction vessel or safety vessel. This experiment can fully consider and study the different influences of various factors, such as different cooling media, cooling channels, injection intensity, immersion heat release, and the promotion of natural circulation capacity of the liquid metal alloy pool, on the experimental results.

[0005] The technical solution of the present invention is as follows: an analysis device for an external heat exhaust system of a liquid metal stack for removing waste heat, comprising a test body and a measuring point support, wherein the measuring point support is located in the test body;

[0006] The test body includes a reaction vessel, a safety vessel, a crater, and the outer wall of the cooling medium flow channel; the reaction vessel is located inside the safety vessel, which is submerged in the crater; the rising flow channel includes two layers, an inner channel located between the reaction vessel and the safety vessel, and an outer channel located between the safety vessel and the outer wall of the cooling medium flow channel.

[0007] The interior of the reaction vessel is a liquid metal alloy pool, and the top cover of the reaction vessel is a sealed top cover above the liquid metal alloy pool. The top cover of the reaction vessel is vertically equipped with electric heating elements from top to bottom, and the heating section is immersed in the liquid metal alloy pool.

[0008] The reaction vessel has a liquid metal alloy filling and draining channel at the bottom.

[0009] The reaction vessel also includes a cooling system, which includes a cooling working fluid injection channel located outside the crater and connected to the rising channel and the outer rising channel. The rising channel and the outer rising channel are respectively equipped with a rising channel injection on / off valve and an outer rising channel injection on / off valve. The top of the rising channel is connected to the inner channel of the rising channel, and the outer rising channel is connected to the outer channel of the rising channel.

[0010] The cooling system also includes an upper injection channel, which is connected to the inner or outer layer of the rising channel via an upper injection channel on / off valve group, and then connected to the inner or outer rising channel; while the subcooled water injection channel and the cold air injection channel are both connected to the upper injection channel, and the connecting pipes are respectively equipped with subcooled water injection on / off valves and cold air injection on / off valves.

[0011] The upper injection channel and the inner layer of the rising channel, as well as the inner rising channel, form the inner channel; while the upper injection channel and the outer layer of the rising channel, as well as the outer rising channel, form the outer channel; and the cooling medium is subcooled water or cold air.

[0012] The cooling medium injection channel is connected to the inside of the crater via a crater immersion injection on / off valve, which controls whether the cooling medium enters the crater.

[0013] The bottom of the sump is connected to a sump drain valve, which is used to drain the residual supercooled water in the sump.

[0014] It also includes a cooling medium discharge chimney, which is surrounded by the outer wall of the cooling medium flow channel, with its upper end connected to the atmospheric space and its lower end connected to the rising flow channel.

[0015] A slit is provided at the top of the pit to submerge the overflow.

[0016] The measuring point support is immersed in a liquid metal alloy pool. The measuring point support includes a measuring point arrangement frame and a fixed frame. The top of the fixed frame is welded to the bottom of the top cover of the reaction vessel. The measuring point arrangement frame has multiple layers along the axial height direction. The measuring point arrangement points are fixed to the measuring point arrangement frame, and each layer of the measuring point arrangement frame has multiple measuring point arrangement points. The lower end of the electric heating element is connected to the fixed frame.

[0017] Each layer of the measuring point arrangement frame is an equilateral triangle structure, with three circular rings at the vertices of the triangles. Electric heating elements are inserted and spot-welded into the circular rings.

[0018] An analytical method for an external heat exhaust system of a container that removes waste heat from a liquid metal stack includes the following steps:

[0019] The pre-trial phase includes,

[0020] S101: Liquid metal alloy is injected into the reaction vessel through the liquid metal alloy filling and draining channel to form a liquid metal alloy pool;

[0021] S102: Turn on the electric heating element;

[0022] S103: Based on the selected test coolant, open the subcooled water injection on / off valve or the cold air injection on / off valve to allow the coolant to reach the front end of the inner rising flow channel injection on / off valve, the outer rising flow channel injection on / off valve, the sump immersion injection on / off valve, and the upper injection flow channel on / off valve group.

[0023] The testing phase includes heat dissipation capacity tests for the inner rising flow channel, heat dissipation capacity tests for the outer rising flow channel, immersion heat release tests for the crater, and tests to promote the natural circulation capacity of the liquid metal alloy pool for the upper injection flow channel.

[0024] The heat dissipation capacity test for the internal rising flow channel includes the following steps:

[0025] S201: Open the injection on / off valve of the inner rising flow channel to allow the cooling medium to be injected into the inner rising flow channel;

[0026] S202: After the cooling working medium is heated by the outer wall of the reaction vessel, it rises and flows in the form of high-temperature gas phase and reaches the rising channel, and finally is discharged from the cooling working medium discharge chimney into the atmosphere.

[0027] S203: The temperature drop of the liquid metal alloy pool 107 is observed and recorded by using high-temperature thermocouples at the measurement points.

[0028] The heat dissipation capacity test for the external rising flow channel includes the following steps:

[0029] S301: Open the injection on / off valve of the outer rising channel to allow the cooling medium to be injected into the outer rising channel;

[0030] S302: After the cooling medium is heated by the outer wall of the safety container, it rises and flows in the form of a high-temperature gas phase and reaches the rising channel; finally, it is discharged into the atmosphere from the cooling medium discharge chimney.

[0031] S303: The temperature drop of the liquid metal alloy pool is observed and recorded by using high-temperature thermocouples at the measurement points.

[0032] The immersion heat release test for the crater includes the following steps:

[0033] S401: Confirm that the heat dissipation capacity test of the internal or external rising flow channel has been started;

[0034] S402: Open the sump immersion injection on / off valve to allow the cooling medium to be injected into the sump;

[0035] S403: The cooling medium is immersed from the outside and fully conducts heat to cool the liquid metal alloy pool. The cooling medium, heated into a high-temperature gas phase, is discharged from the top of the crater.

[0036] S404: By setting up measurement points, observe and record the temperature drop of the liquid metal alloy pool, and determine whether the immersion heat release test in the sump enhances the temperature drop of the liquid metal alloy pool compared to when no sump is used.

[0037] In S403, the gap at the top of the sump for submerging the overflow is used to control the submersion level.

[0038] The test to enhance the natural circulation capability of the liquid metal alloy pool in the upper injection channel includes the following steps:

[0039] S501: Confirm that the heat dissipation capacity test of the internal or external rising flow channel has been started.

[0040] S502: Close the inner rising channel injection on / off valve or the outer rising channel injection on / off valve; open the upper injection channel on / off valve group to allow the cooling medium to be injected into the upper region of the inner rising channel or the outer rising channel to cool the upper liquid metal alloy in the cooling liquid metal alloy pool.

[0041] S503: By setting up measurement points, observe and record the temperature drop of the liquid metal alloy pool, and compare it with the heat dissipation capacity test for the inner rising flow channel and the heat dissipation capacity test for the outer rising flow channel.

[0042] After the experiment is completed, the following steps are included:

[0043] S601: Turn off the electric heating element

[0044] S602: Drain the liquid metal alloy in the liquid metal alloy pool through the liquid metal alloy filling and draining channel;

[0045] S603: The residual subcooled water and hot air in the inner and outer rising channels and rising channels are discharged into the atmosphere through the cold air injection channel, and then all shut-off valves opened during the test are closed.

[0046] If there is residual supercooled water in the storage pit, open the storage pit drain valve and drain the residual supercooled water.

[0047] The cooling medium is subcooled water or cold air.

[0048] The significant advantages of this invention are:

[0049] 1. This invention can simultaneously study the differences in cooling capacity between injecting supercooled water or cold air as the cooling medium for the external heat exhaust system of the container. Furthermore, the cooling medium can be injected into the flow channel between the stack container and the safety container, or into the flow channel outside the safety container. By controlling the number of flow channels used, the geometric design parameters of the external heat exhaust system of different stack types can be modeled. The combination of the above-mentioned cooling medium and cooling flow channel can cover all the design schemes of the existing external heat exhaust system of liquid metal stack containers.

[0050] 2. This invention provides test conditions for crater immersion heat release testing. By injecting cooling working fluid into the crater and fully immersing the liquid metal alloy pool to the required liquid level, the cooling assistance capability of crater immersion on the external heat exhaust system of the container and the liquid metal alloy pool is evaluated.

[0051] 3. The present invention provides test conditions for promoting the natural circulation capacity of a liquid metal alloy pool. By directly injecting a cooling medium into the upper flow channel area of ​​the external heat exhaust system of the container and cooling the upper liquid metal alloy of the liquid metal alloy pool, the effect of the above injection scheme on promoting the natural circulation capacity of the liquid metal alloy pool is evaluated.

[0052] In summary, this experimental setup can conduct research on the ability of container external heat exhaust systems to remove residual heat from accidents under different cooling conditions and design schemes. The entire experimental setup is feature-rich, safe, reliable, and reusable, making it possible to conduct comprehensive experimental research and scheme demonstration on the external heat exhaust system of liquid metal stack containers. Attached Figure Description

[0053] Figure 1 The main view of the test apparatus for designing and analyzing the external heat exhaust system of the container.

[0054] Figure 2 Schematic diagram of the upper injection flow channel on / off valve assembly

[0055] Figure 3 This is the main view of the internal measurement point support.

[0056] The markings in the diagram and their corresponding component names are as follows:

[0057] In the diagram: reaction vessel 101, safety vessel 102, rising flow channel 103, crater 104, reaction vessel top cover 105, electric heating element 106, liquid metal alloy pool 107, cooling medium injection channel 108, inner rising flow channel 109, outer rising flow channel 110, liquid metal alloy filling and discharging channel 111, supercooled water injection shut-off valve 112, cold air injection shut-off valve 113, crater immersion injection shut-off valve 114, inner rising flow channel injection shut-off valve 115, outer rising flow channel injection shut-off valve 116, supercooled water injection channel 117, cold air injection channel 118, cooling medium discharge chimney 119, cooling medium flow channel outer wall 120, upper injection channel 121, upper injection channel shut-off valve assembly 122, crater drain valve 123;

[0058] Measuring point layout frame 201, measuring point layout location 202, fixed frame 203. Detailed Implementation

[0059] Many specific details are set forth in the following description to provide a full understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of this application; therefore, this application is not limited to the specific embodiments disclosed below.

[0060] The terminology used in one or more embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the scope of one or more embodiments of this application. The singular forms “a,” “the,” and “the” used in one or more embodiments of this application and in the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” used in one or more embodiments of this application refers to and includes any or all possible combinations of one or more associated listed items.

[0061] It should be understood that although the terms first, second, etc., may be used to describe various information in one or more embodiments of this application, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first may also be referred to as second without departing from the scope of one or more embodiments of this application, and similarly, second may also be referred to as first.

[0062] The present invention will now be described in detail with reference to the accompanying drawings and embodiments:

[0063] An analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat from a container includes a test body and a measuring point support. The test body is a test device that simulates the operation of the external heat exhaust system of the container. The device includes: reaction vessel 101, safety vessel 102, rising flow channel 103, pile pit 104, reaction vessel top cover 105, electric heating element 106, liquid metal alloy pool 107, cooling medium injection flow channel 108, inner rising flow channel 109, outer rising flow channel 110, liquid metal alloy filling and discharging flow channel 111, subcooled water injection on / off valve 112, cold air injection on / off valve 113, pile pit immersion injection on / off valve 114, inner rising flow channel injection on / off valve 115, outer rising flow channel injection on / off valve 116, subcooled water injection flow channel 117, cold air injection flow channel 118, cooling medium discharge chimney 119, cooling medium flow channel outer wall 120, upper injection flow channel 121, upper injection flow channel on / off valve group 122, and pile pit drain valve 123.

[0064] like Figure 3 As shown, the measuring point bracket is a measuring point fixing device arranged in the liquid metal alloy pool, used to fix the temperature measuring points in the liquid metal alloy. The device includes: measuring point arrangement frame 201, measuring point arrangement position 202, and fixing frame 203.

[0065] The test body is a test device simulating a liquid metal alloy pool and a heat exhaust system of a reactor vessel in a liquid metal reactor. The reaction vessel 101 is a directly pressurized reactor vessel simulating a primary loop reactor pool, and the safety vessel 102 is a safety pressure vessel simulating a protective reactor vessel. The rising channel 103 is a heating rising channel for the cooling working fluid in the heat exhaust system of the reactor vessel, and is divided into inner and outer layers. The inner channel is located between the reaction vessel 101 and the safety vessel 102, and is used for heating the rising channel when the cooling working fluid directly cools the reaction vessel 101. The outer channel is located between the safety vessel 102 and the outer wall 120 of the cooling working fluid channel, and is used for heating the rising channel when the cooling working fluid cools the safety vessel 102. In this case, the inner channel is used to simulate the area between the reaction vessel 101 and the safety vessel 102. The air gap layer; the crater 104 is the cavity of the immersion safety container 102, used to carry out crater immersion heat release test. The crater immersion heat release test involves the flow of cooling working fluid in the rising channel 103, while simultaneously injecting cooling working fluid into the crater 104, so as to realize the immersion of the safety container 103 by the cooling working fluid in the crater 104, and to study the effect of immersion on the enhancement of heat dissipation capacity. The top of the crater 104 is provided with a slit for immersion overflow; the top cover 105 of the reaction vessel is the upper sealed top cover of the liquid metal alloy pool 107. The top cover 105 of the reaction vessel is vertically equipped with electric heating elements 106 from top to bottom. Its heating section is immersed in the liquid metal alloy pool 107. The electric heating elements 106 release heat according to the set specified heating power curve to simulate the heat release process of core decay heat in the liquid metal alloy pool;

[0066] The cooling medium injection channel 108 is the inlet channel for the cooling medium. After the cooling medium is injected into the channel, it can be selected to enter the inner rising channel 109 or the outer rising channel 110. The control method is to operate the opening and closing of the inner rising channel injection on / off valve 115 or the outer rising channel injection on / off valve 116.

[0067] The liquid metal alloy filling and discharging channel 111 is a channel for controlling the filling or discharging of liquid metal alloy into the reaction vessel 101, and its front end is connected to the liquid metal alloy filling and discharging system.

[0068] The subcooled water injection on / off valve 112 controls the opening and closing of the subcooled water supply in the subcooled water injection channel 117, and the cold air injection on / off valve 113 controls the opening and closing of the cold air supply in the cold air injection channel 118; the crater immersion injection on / off valve 114 controls whether the cooling medium enters the crater 104 to determine whether to carry out heat dissipation capacity test and crater immersion heat release test; the cooling medium discharge chimney 119 is surrounded by the outer wall 120 of the cooling medium channel, and its upper end is connected to the atmospheric space to discharge the heated gaseous cooling medium in the rising channel 103;

[0069] The upper injection channel 121 is used to study the direct injection of cooling medium into the upper channel area of ​​the external heat exhaust system of the container and to cool the upper liquid metal alloy of the liquid metal alloy pool 107. It promotes the testing of the natural circulation capability of the liquid metal alloy pool 107. The injection on / off is controlled by the upper injection channel on / off valve group 122. The upper injection channel on / off valve group 122 has several on / off valves arranged in both the inner and outer channels. Each on / off valve is used to control whether there is cooling medium flow in several sub-channels of the channel, thereby controlling the total cross-sectional area of ​​the cooling medium flow, so as to model the geometric design parameters of the external heat exhaust system of the container for different stack types. The stack pit drain valve 123 is used to drain the residual supercooled water in the stack pit 104.

[0070] like Figure 3 As shown, the measuring point support is a measuring point arrangement support immersed in the liquid metal alloy pool 107. Its measuring point arrangement frame 201 has a total of 4 layers along the axial height direction. Each layer is an equilateral triangle structure with three rings at the vertices of the triangles. Electric heating elements 106 are inserted and spot-welded into the rings. The measuring point arrangement points 202 are several high-temperature resistant thermocouple measuring points fixed on each layer of the measuring point arrangement frame 201 for monitoring the temperature change of the liquid metal alloy pool 107. The fixing frame 203 is a support frame that connects and fixes each layer of the measuring point arrangement frame 201. Its top is welded to the bottom of the reaction vessel top cover 105.

[0071] The test method for the design and analysis test device of the container external heat exhaust system for removing residual heat from a liquid metal stack accident, in the test preparation stage, includes: 1) confirming that the cooling medium for this test is subcooled water or cold air. If it is subcooled water, ensure that the water supply to the subcooled water injection channel 117 is unobstructed; if it is cold air, ensure that the air supply to the cold air injection channel 118 is unobstructed; 2) confirming that the liquid metal supply to the liquid metal alloy charging and discharging channel 111 is unobstructed; 3) confirming that the simulated decay heat power curve of the electric heating element 106 is set correctly; 4) confirming that the connection between the rear end of the cooling medium exhaust chimney 119 and the atmospheric space is unobstructed; 5) confirming which channels the cooling medium is injected into for this test, specifically including the heat exhaust capacity test of the inner rising channel 109, the heat exhaust capacity test of the outer rising channel 110, the heat release test of the immersion in the stack pit 104, and the test of the natural circulation capacity promotion of the liquid metal alloy pool in the upper injection channel 121.

[0072] In the pre-test stage, 1) liquid metal alloy is injected into the reaction vessel 101 through the liquid metal alloy filling and draining channel 111 to form a liquid metal alloy pool 107 that meets the liquid level requirements; 2) then the electric heating element 106 is turned on and the initial temperature and decay heat power curve of the liquid metal alloy pool 107 meet the test requirements; 3) according to the selected test cooling medium, the subcooled water injection on / off valve 112 or the cold air injection on / off valve 113 is opened to ensure that the cooling medium fully reaches the front end of each injection valve. The injection valves include the inner rising channel injection on / off valve 115, the outer rising channel injection on / off valve 116, the immersion injection on / off valve 114, and the upper injection channel on / off valve group 122.

[0073] During the test phase, the heat dissipation capacity of the inner rising channel 109 was tested as follows: 1) The inner rising channel injection on / off valve 115 was opened to allow the cooling medium to be injected into the inner rising channel 109; 2) After being heated by the outer wall of the reaction vessel 101, the cooling medium rose and flowed in the form of a high-temperature gas phase, cooling the reaction vessel 101 and reaching the rising channel 103; 3) Finally, the cooling medium was discharged from the cooling medium discharge chimney 119 into the atmospheric space; 4) The temperature drop of the liquid metal alloy pool 107 was observed and recorded by using the high-temperature thermocouple measuring points 202.

[0074] During the test phase, the heat dissipation capacity of the outer rising channel 110 was tested by: 1) opening the injection on / off valve 116 of the outer rising channel to allow the cooling medium to be injected into the outer rising channel 110; 2) after being heated by the outer wall of the safety container 102, the cooling medium rises and flows in the form of a high-temperature gas phase and reaches the rising channel 103; 3) finally being discharged into the atmosphere from the cooling medium discharge chimney 119; 4) observing and recording the temperature drop of the liquid metal alloy pool 107 through the high-temperature thermocouple measuring points of the measuring point arrangement 202.

[0075] During the test phase, for the immersion heat release test of the crater 104, 1) it was confirmed that the heat dissipation capacity test of the inner rising channel 109 or the outer rising channel 110 had begun; 2) the immersion injection shut-off valve 114 was opened to allow the cooling medium to be injected into the crater 104; 3) the cooling medium was immersed from the outside and fully conducted heat to cool the liquid metal alloy pool 107. The gap at the top of the crater 104 for immersion overflow could be used to control the immersion liquid level height, and the cooling medium heated into a high-temperature gas phase could also be discharged from the top of the crater 104; 4) the temperature drop of the liquid metal alloy pool 107 was observed and recorded through the high-temperature thermocouple measuring points of the measuring point arrangement 202, and it was determined whether the immersion heat release test enhanced the temperature drop of the liquid metal alloy pool 107.

[0076] During the experimental phase, for the natural circulation capacity enhancement test of the liquid metal alloy pool in the upper injection channel 121, 1) it was confirmed that the heat dissipation capacity test of the inner rising channel 109 or the outer rising channel 110 had begun; 2) the inner rising channel injection on / off valve 115 or the outer rising channel injection on / off valve 116 was closed; the upper injection channel on / off valve group 122 was opened to allow the cooling medium to be injected into the upper region of the inner rising channel 109 or the outer rising channel 110 to enhance the cooling of the upper liquid metal alloy in the liquid metal alloy pool 107; 3) the temperature drop of the liquid metal alloy pool 107 was observed and recorded through the high-temperature thermocouple measuring points of the measuring point arrangement 202, and it was determined whether the natural circulation capacity enhancement test of the liquid metal alloy pool enhanced the natural circulation capacity of the liquid metal alloy pool 107.

[0077] Specifically, the cooling effect of using the inner rising flow channel 109 is compared with that of the cooling medium entering the inner flow channel from the upper injection flow channel 121, and the cooling effect of using the outer rising flow channel 110 is compared with that of the cooling medium entering the outer flow channel from the upper injection flow channel 121, that is, to achieve a comparison under the same conditions and control variables.

[0078] Specifically, the natural circulation capability refers to the cooling medium entering from bottom to top through the inner rising flow channel injection on / off valve 115 and the outer rising flow channel injection on / off valve 116, which cools the lower part of the reaction vessel 101. However, since substances with higher temperatures naturally tend to rise, the cooling effect in the upper part of the reaction vessel 101 is poor. But because the upper injection channel 121 is used, the cooling medium cools the upper part of the reaction vessel 101, while the liquid metal alloy in the lower part of the reaction vessel 101 that has not been sufficiently cooled flows upward, forming a natural circulation, so that the liquid metal alloy pool 107 is sufficiently cooled.

[0079] After the test is completed, 1) turn off the heating power of the electric heating element 106; 2) drain the liquid metal alloy in the liquid metal alloy pool 107 through the liquid metal alloy filling and draining channel 111 by gravity; 3) discharge the residual subcooled water and hot air in the inner rising channel 109, outer rising channel 110 and rising channel 103 into the atmosphere through the cold air injection channel 118, and then close all the shut-off valves opened during the test; 4) if there is residual subcooled water in the pile pit 104, open the pile pit drain valve 123 and drain the residual subcooled water.

[0080] For liquid lead-based alloys, the reaction vessel 101 is filled or discharged through the liquid metal alloy filling and discharging channel 111 to form a liquid metal alloy pool 107. Then, the liquid metal alloy pool 107 is heated and maintained to the required temperature value or heating power curve by the electric heating element 106.

[0081] When the cooling medium is subcooled water, it enters the cooling medium injection channel 108 or the upper injection channel 121 through the subcooled water injection channel 117 and the subcooled water injection shut-off valve 112. In this case, 1) if injected from the bottom up through the inner rising channel, the subcooled water sequentially passes through the cooling medium injection channel 108, the inner rising channel injection shut-off valve 115, and the inner rising channel 109, being heated into water vapor and rising, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119; 2) similarly, if injected from the bottom up through the outer rising channel, the subcooled water sequentially passes through the cooling medium injection channel 108, the outer rising channel injection shut-off valve 116, and the outer rising channel 110, being heated into water vapor and rising, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119; 2) similarly, if injected from the bottom up through the outer rising channel, the subcooled water sequentially passes through the cooling medium injection channel 108, the outer rising channel injection shut-off valve 116, and the outer rising channel 110, being heated into water vapor and rising, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119. 3) If injected from the upper inner or outer injection channel, the supercooled water passes through the upper injection channel 121 and the upper injection channel on / off valve group 122 in sequence, and then flows into the inner rising channel 109 or the outer rising channel 110. During the process, it is heated into water vapor and floats up, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119; 4) For the immersion heat release process of the sump 104, the supercooled water is injected directly into the sump 104 through the cooling medium injection channel 108 and the sump immersion injection on / off valve 114 in sequence. The water vapor that is heated into a high-temperature gas phase can then be discharged from the top of the sump 104.

[0082] When the cooling medium is cold air, it enters the cooling medium injection channel 108 or the upper injection channel 121 through the cold air injection channel 118 and the cold air injection on / off valve 113. In this case, 1) if injected from the bottom upwards through the inner rising channel, the cold air sequentially passes through the cooling medium injection channel 108, the inner rising channel injection on / off valve 115, and the inner rising channel 109, being heated and rising during the process, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119; 2) similarly, if injected from the bottom upwards through the outer rising channel, the cold air sequentially passes through the cooling medium injection channel 108, the outer rising channel injection on / off valve 116, and the outer rising channel 110, during which... 3) If injected from the upper inner or outer injection channel, the cold air passes through the upper injection channel 121 and the upper injection channel on / off valve group 122 in sequence, and then flows into the inner rising channel 109 or the outer rising channel 110. During the process, it is heated and floated, and finally discharged through the rising channel 103 to the cooling medium discharge chimney 119; 4) For the immersion heat release process of the pile pit 104, the supercooled air is directly injected into the pile pit 104 through the cooling medium injection channel 108 and the pile pit immersion injection on / off valve 114 in sequence. The cold air that is heated to a high temperature can then be discharged from the top of the pile pit 104.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

[0084] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that this application is not limited to the described order of actions, as some steps may be performed in other orders or simultaneously according to this application. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to this application.

[0085] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0086] The preferred embodiments disclosed above are merely illustrative of this application. The optional embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this application. These embodiments are selected and specifically described in this application to better explain the principles and practical applications of this application, thereby enabling those skilled in the art to better understand and utilize this application.

Claims

1. An analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat, characterized in that: It includes the test body and the measuring point support, with the measuring point support located inside the test body; The test body includes a reaction vessel (101), a safety vessel (102), a crater (104), and an outer wall surface (120) of the cooling medium flow channel; the reaction vessel (101) is located inside the safety vessel (102), and the safety vessel (102) is submerged in the crater (104); the rising flow channel (103) includes inner and outer layers, with the inner layer channel located between the reaction vessel (101) and the safety vessel (102), and the outer layer channel located between the safety vessel (102) and the outer wall surface (120) of the cooling medium flow channel; The interior of the reaction vessel (101) is a liquid metal alloy pool (107), and the top cover (105) of the reaction vessel is a sealed top cover on the upper part of the liquid metal alloy pool (107). The top cover (105) of the reaction vessel is vertically equipped with an electric heating element (106) from top to bottom, and its heating section is immersed in the liquid metal alloy pool (107). The reaction vessel (101) has a liquid metal alloy filling and draining channel (111) at the lower end.

2. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 1, characterized in that: The reaction vessel (101) also includes a cooling system, which includes a cooling working fluid injection channel (108). The cooling working fluid injection channel (108) is located outside the pile pit (104) and is connected to the rising channel (109) and the outer rising channel (110). There are rising channel injection on / off valves (115) and outer rising channel injection on / off valves (116) in the rising channel (109) and the outer rising channel (110), respectively. The top of the rising channel (109) is connected to the inner channel of the rising channel (103), and the outer rising channel (110) is connected to the outer channel of the rising channel (103).

3. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 2, characterized in that: The cooling system also includes an upper injection channel (121), which is connected to the inner or outer layer of the rising channel (103) through an upper injection channel on / off valve group (122), and then connected to the inner rising channel (109) or the outer rising channel (110); while the subcooled water injection channel (117) and the cold air injection channel (118) are both connected to the upper injection channel (121), and the connecting pipes are respectively connected to the subcooled water injection on / off valve (112) and the cold air injection on / off valve (113).

4. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 3, characterized in that: The upper injection channel (121) and the inner layer of the rising channel (103), as well as the inner rising channel (109), form an inner channel; while the upper injection channel (121) and the outer layer of the rising channel (103), as well as the outer rising channel (110), form an outer channel; and the cooling medium is subcooled water or cold air.

5. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 4, characterized in that: The cooling medium injection channel (108) is connected to the inside of the crater (104) through the crater immersion injection on / off valve (114), which controls whether the cooling medium enters the crater (104).

6. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 5, characterized in that: The bottom of the storage pit (104) is connected to the storage pit drain valve (123), which is used to drain the residual supercooled water in the storage pit (104).

7. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 6, characterized in that: It also includes a cooling medium discharge chimney (119), which is surrounded by the outer wall of the cooling medium flow channel (120), with its upper end connected to the atmospheric space and its lower end connected to the rising flow channel (103).

8. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 7, characterized in that: A slit is provided at the top of the pit (104) to submerge the overflow.

9. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 7, characterized in that: The measuring point support is immersed in the liquid metal alloy pool (107). The measuring point support includes a measuring point arrangement frame (201) and a fixed frame (203). The top of the fixed frame (203) is welded to the bottom of the reaction vessel top cover (105). The measuring point arrangement frame (201) has multiple layers along the axial height direction. The measuring point arrangement points (202) are fixed to the measuring point arrangement frame (201), and each layer of the measuring point arrangement frame (201) has multiple measuring point arrangement points (202). The lower end of the electric heating element (106) is connected to the fixed frame (203).

10. The analytical device for an external heat exhaust system of a liquid metal stack for removing waste heat according to claim 9, characterized in that: The measuring point arrangement frame (201) has an equilateral triangle structure in each layer, with three rings at the vertices of the triangles. Electric heating elements (106) are inserted and spot-welded into the rings.

11. An analytical method for an external heat exhaust system of a liquid metal stack for removing waste heat, using the apparatus as described in claim 10, characterized in that: Includes the following steps: The pre-trial phase includes, S101: Liquid metal alloy is injected into the reaction vessel (101) through the liquid metal alloy filling and draining channel (111) to form a liquid metal alloy pool (107); S102: Turn on the electric heating element (106); S103: According to the selected test coolant, open the subcooled water injection shut-off valve (112) or cold air injection shut-off valve (113) to allow the coolant to reach the front end of the inner rising channel injection shut-off valve (115), the outer rising channel injection shut-off valve (116), the sump immersion injection shut-off valve (114), and the upper injection channel shut-off valve group (122). The testing phase includes heat dissipation capacity tests for the inner rising channel (109), heat dissipation capacity tests for the outer rising channel (110), heat release tests for the immersion immersion of the sump (104), and tests to promote the natural circulation capacity of the liquid metal alloy pool for the upper injection channel (121).

12. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 11, characterized in that: The heat dissipation capacity test for the inner rising flow channel (109) includes the following steps: S201: Open the injection on / off valve (115) of the inner rising flow channel to allow the cooling working fluid to be injected into the inner rising flow channel (109); S202: After the cooling working medium is heated by the outer wall of the reaction vessel (101), it rises and flows in the form of high temperature gas phase and reaches the rising channel (103), and finally is discharged from the cooling working medium discharge chimney (119) into the atmospheric space. S203: The temperature drop of the liquid metal alloy pool (107) is observed and recorded by using the high-temperature thermocouple measuring points (202) of the measuring point arrangement.

13. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 11, characterized in that: The heat dissipation capacity test for the outer rising channel (110) includes the following steps: S301: Open the injection on / off valve (116) of the external rising flow channel to allow the cooling working fluid to be injected into the external rising flow channel (110); S302: After the cooling medium is heated by the outer wall of the safety container (102), it rises and flows in the form of a high-temperature gas phase and reaches the rising channel (103); finally, it is discharged from the cooling medium discharge chimney (119) into the atmospheric space. S303: The temperature drop of the liquid metal alloy pool (107) is observed and recorded by using the high-temperature thermocouple measuring points (202) of the measuring point arrangement.

14. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 12 or 13, characterized in that: The immersion heat release test for the crater (104) includes the following steps: S401: Confirm that the heat dissipation capacity test of the inner rising channel (109) or the outer rising channel (110) has been started; S402: Open the sump immersion injection shut-off valve (114) to allow the cooling medium to be injected into the sump (104); S403: The cooling medium is immersed from the outside and fully conducts heat to cool the liquid metal alloy pool 107. The cooling medium, which is heated into a high-temperature gas phase, is discharged from the top of the pile pit (104). S404: By setting up measurement points (202), observe and record the temperature drop of the liquid metal alloy pool (107), and determine whether the immersion heat release test in the sump enhances the temperature drop of the liquid metal alloy pool (107) compared to when the sump (104) is not used.

15. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 14, characterized in that: In S403, the gap at the top of the sump (104) that submerges the overflow is used to control the submersion level.

16. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 12 or 13, characterized in that: The test to enhance the natural circulation capability of the liquid metal alloy pool in the upper injection channel (121) includes the following steps: S501: Confirm that the heat dissipation capacity test of the inner rising channel (109) or the outer rising channel (110) has been started; S502: Close the inner rising channel injection shut-off valve (115) or the outer rising channel injection shut-off valve (116); open the upper injection channel shut-off valve group (122) to allow the cooling medium to be injected into the upper region of the inner rising channel (109) or the outer rising channel (110) to cool the upper liquid metal alloy in the cooling liquid metal alloy pool (107); S503: By setting up measurement points (202), observe and record the temperature drop of the liquid metal alloy pool (107), and compare it with the heat dissipation capacity test for the inner rising channel (109) and the heat dissipation capacity test for the outer rising channel (110).

17. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 11, characterized in that: After the experiment is completed, the following steps are included: S601: Turn off the electric heating element (106); S602: The liquid metal alloy in the liquid metal alloy pool (107) is drained away through the liquid metal alloy filling and draining channel 111; S603: The residual subcooled water and hot air in the inner rising channel (109), outer rising channel (110), and rising channel (103) are discharged into the atmospheric space through the cold air injection channel (118), and then all shut-off valves opened during the test are closed.

18. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 17, characterized in that: If there is residual supercooled water in the storage pit (104), open the storage pit drain valve (123) and drain the residual supercooled water.

19. The method for analyzing an external heat exhaust system for a liquid metal stack to remove waste heat according to claim 11, characterized in that: The cooling medium is subcooled water or cold air.

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