Testing device for simulating temperature pulsation and thermal stratification phenomenon of lead-bismuth medium

Abstract

The utility model discloses a test device for simulating temperature pulsation and thermal stratification of a lead-bismuth medium. The test device comprises a storage tank, a conveying pipeline, at least two heating branches, a test section and a return pipeline, the at least two heating branches are arranged in parallel and are connected between the conveying pipeline and the test section, and the return pipeline is connected between the test section and the storage tank; the conveying pipeline conveys the lead-bismuth alloy in the storage tank to the two heating branches, each heating branch heats the lead-bismuth alloy to a test temperature and then feeds the lead-bismuth alloy into the test section, and the lead-bismuth alloys at different test temperatures are mixed in the test section and then return to the storage tank through the return pipeline. According to the utility model, the storage tank, the conveying pipeline, the heating branch, the test section and the like are connected, so that the lead-bismuth alloy flows in the test device and enters the test section to be mixed at different temperatures, and the temperature pulsation of a solid structural member in a cold and hot fluid mixing process can be simulated; and determining the distribution rules of temperature, flow velocity, turbulence intensity and the like in the flow field and the mechanism of a thermal stratification phenomenon and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power test, in particular to a test device for simulating temperature pulsation and thermal stratification phenomena of a lead-bismuth medium. Background Art

[0002] Lead-bismuth fast reactors belong to the fourth generation of nuclear power technology. Lead-bismuth alloys have the characteristics of high thermal conductivity, low melting point, high boiling point and high inherent safety. Therefore, lead-bismuth fast reactors can achieve high power density even when operating under normal pressure conditions. However, due to the uneven distribution of nuclear reactor core components and power, hot and cold fluids will come into contact in areas such as the core outlet. When non-isothermal fluids mix with each other, strong turbulent mixing will cause random temperature fluctuations in the fluid near the wall. This phenomenon is called temperature pulsation. The temperature fluctuations of the fluid will be transmitted to the solid wall to produce alternating thermal stress and thermal fatigue, which will reduce the strength of the wall structure or even cause damage. This phenomenon is called thermal oscillation.

[0003] However, there are few studies on the temperature pulsation and thermal stratification phenomena of lead-bismuth media. The turbulent heat transfer characteristics in the lead-bismuth fast reactor pool are quite different from those in the water reactor. Some traditional temperature fluctuation laws for water reactors are no longer applicable to lead-bismuth fast reactors. Utility Model Content

[0004] The technical problem to be solved by the utility model is to provide a test device for simulating the temperature pulsation and thermal stratification phenomenon of lead-bismuth medium.

[0005] The technical solution adopted by the utility model to solve the technical problem is: to provide a test device for simulating the temperature pulsation and thermal stratification phenomenon of lead-bismuth medium, including a storage tank for storing lead-bismuth alloy, a conveying pipeline, at least two heating branches, a test section and a reflux pipeline;

[0006] At least two of the heating branches are arranged in parallel and connected between the delivery pipeline and the test section, and the return pipeline is connected between the test section and the storage tank;

[0007] The conveying pipeline conveys the lead-bismuth alloy in the storage tank to the two heating branches. Each heating branch heats the lead-bismuth alloy to the test temperature and then conveys it to the test section. The lead-bismuth alloys at different test temperatures are mixed in the test section and then returned to the storage tank through the reflux pipeline.

[0008] Preferably, each of the heating branches comprises a heating pipe, a branch heater arranged on the heating pipe, a temperature measuring unit and a flow meter.

[0009] Preferably, the temperature measuring unit comprises a branch thermometer, and the branch thermometer is located at the inlet end and / or the outlet end of the branch heater on the heating pipe.

[0010] Preferably, the flow meter is a Venturi flow meter.

[0011] Preferably, the test device further comprises a flow meter calibration barrel; the flow meter calibration barrel is connected between the heating branch and the delivery pipeline.

[0012] Preferably, the storage tank is provided with a heating unit for heating and melting the lead-bismuth alloy; the heating unit comprises a heating wire wound around the storage tank.

[0013] Preferably, the delivery pipeline includes a delivery pipe and a delivery pump arranged on the delivery pipe;

[0014] The conveying pipeline is also provided with a preheater for heating the lead-bismuth alloy and at least one thermometer; the thermometer is located at the inlet end and / or outlet end of the preheater on the conveying pipeline.

[0015] Preferably, the reflux pipeline includes a reflux pipe and a cooler arranged on the reflux pipe for cooling the lead-bismuth alloy.

[0016] Preferably, the test device further comprises a cooling circuit connected to the cooler and providing a cooling source for the cooler.

[0017] Preferably, the cooling circuit comprises a thermal oil tank for storing thermal oil, a thermal oil pump, an oil inlet pipeline and an oil return pipeline; the oil inlet pipeline is connected between the outlet of the thermal oil tank and the cooler, and the oil return pipeline is connected between the inlet of the thermal oil tank and the cooler;

[0018] The heat transfer oil pump is arranged on the oil inlet pipeline or the oil return pipeline.

[0019] Preferably, the test device further comprises a high-pressure gas providing unit;

[0020] The high-pressure gas supply unit is connected to the storage tank and delivers high-pressure argon gas into the storage tank to press the lead-bismuth alloy in the storage tank into the delivery pipeline.

[0021] Preferably, the high-pressure gas supply unit comprises a high-pressure gas tank and a gas delivery pipeline connected between the high-pressure gas tank and a storage tank.

[0022] Preferably, a gas heater and a pressure gauge are provided on the gas supply pipeline.

[0023] The beneficial effects of the utility model are as follows: a test device is formed by connecting a storage tank, a conveying pipeline, a heating branch and a test section, in which a lead-bismuth alloy flows and enters the test section for mixing at different temperatures, so as to simulate the temperature pulsation of solid structural parts during the mixing process of cold and hot fluids, determine the distribution law of temperature, flow velocity, turbulence intensity, etc. in the flow field, and the mechanism of thermal stratification phenomenon, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments, in which:

[0025] Figure 1 It is a schematic diagram of the connection structure of a test device for simulating the temperature pulsation and thermal stratification phenomenon of a lead-bismuth medium according to an embodiment of the utility model;

[0026] Figure 2 It is a schematic diagram of the structure of the utility model with the pipeline as the test section;

[0027] Figure 3 It is a temperature pulsation curve diagram obtained by testing with the pipeline as the test section in the utility model;

[0028] Figure 4 It is a flow velocity pulsation curve diagram obtained by conducting a test using a pipeline as a test section in the utility model. DETAILED DESCRIPTION

[0029] In order to have a clearer understanding of the technical features, purposes and effects of the present utility model, the specific implementation methods of the present utility model are now described in detail with reference to the accompanying drawings.

[0030] like Figure 1 As shown, a test device for simulating temperature pulsation and thermal stratification phenomenon of a lead-bismuth medium according to an embodiment of the utility model may include a storage tank 10, a conveying pipeline 20, at least two heating branches 30 arranged in parallel, a test section 40 and a reflux pipeline 50 which are sequentially connected to form a loop.

[0031] The storage tank 10 is used to store the lead-bismuth alloy. The parallel heating branch 30 is connected between the delivery pipeline 20 and the test section 40, and the reflux pipeline 50 is connected between the test section 40 and the storage tank 10. The delivery pipeline 20 delivers the lead-bismuth alloy in the storage tank 10 to the two heating branches 30. Each heating branch 30 heats the lead-bismuth alloy to the test temperature and then delivers it to the test section 40. The lead-bismuth alloys at different test temperatures are mixed in the test section 40 and then returned to the storage tank 10 through the reflux pipeline 50.

[0032] Specifically, the lead-bismuth alloy is placed in the storage tank 10 in a solid state, and after the storage tank 10 is placed, the storage tank 10 is strictly sealed. The lead-bismuth alloy transported by the transport pipeline 20 is in a liquid state, so the storage tank 10 is provided with a heating unit (not shown) for heating and melting the lead-bismuth alloy; the heating unit includes but is not limited to a heating wire wound on the outside of the storage tank 10. The heating wire generates heat after being powered on, and can heat and melt the lead-bismuth alloy in the storage tank 10.

[0033] The storage tank 10 is provided with a thermometer 13 to detect the temperature of the lead-bismuth alloy therein.

[0034] The delivery pipeline 20 may include a delivery pipe 21 and a delivery pump 22 disposed on the delivery pipe 21. The delivery pipe 21 is connected to the storage tank 10 at a position below the liquid level of the lead-bismuth alloy in the storage tank 10 to output a sufficient amount of lead-bismuth alloy for testing. The delivery pump 22 pumps the lead-bismuth alloy into the heating branch 30 to provide power for the stable flow of the lead-bismuth alloy in the entire circuit. The delivery pump 22 is preferably a permanent magnet pump.

[0035] The conveying pipeline 21 may further be provided with a preheater 23 and at least one thermometer. The preheater 23 is used to heat the lead-bismuth alloy on the conveying pipeline 21, and preheat the lead-bismuth alloy entering the heating branch 30. The thermometer may be provided at the inlet end and / or outlet end of the preheater 23. For example, in one embodiment, Figure 1 As shown, the thermometer includes a first thermometer 24 and a second thermometer 25; the first thermometer 24 and the second thermometer 25 are respectively located at the inlet end and the outlet end of the preheater 23 on the conveying pipeline 21, and are respectively used to detect the temperature of the lead-bismuth alloy before entering the preheater 23 and the temperature after passing through the preheater 23, so that obtaining relevant data is helpful for conducting, monitoring and facilitating real-time adjustment of the test.

[0036] The preheater 23, the first thermometer 24 and the second thermometer 25 are all located at the output end of the feed pump 22 on the delivery pipeline 21. The heating temperature of the preheater 23 is 200°C to 400°C.

[0037] Each heating branch 30 may specifically include a heating pipe 31 , a branch heater 32 disposed on the heating pipe 31 , a temperature measuring unit, and a flow meter 34 .

[0038] The heating pipe 31 is connected to the delivery pipe 21 and receives the lead-bismuth alloy delivered by the delivery pipe 21. The branch heater 32 on the heating pipe 31 is used to heat the lead-bismuth alloy flowing inside the heating pipe 31, so that the lead-bismuth alloy is heated to the test temperature required for the test. The test temperature can be measured and monitored in real time by the temperature measurement unit.

[0039] The temperature measuring unit includes at least one branch thermometer 33, which is used to measure the temperature of the lead-bismuth alloy in the heating pipe 31, including at least one of the temperature before being heated by the branch heater 32 and the temperature after being heated by the branch heater 32. Preferably, the temperature measuring unit includes two branch thermometers 33, which are located at the inlet end and the outlet end of the branch heater 32 on the heating pipe 31, respectively, and are used to measure the temperature of the lead-bismuth alloy before entering the branch heater 32 and the temperature after passing through the branch heater 32, respectively. The temperature measurement of the inlet and outlet ends of the branch heater 32 by the branch thermometer 33 can accurately obtain the temperature of the lead-bismuth alloy before heating and the temperature of the lead-bismuth alloy after heating in real time, and thus can know in real time whether the temperature rise of the lead-bismuth alloy reaches the test temperature required for the test.

[0040] The two heating branches 30 heat the lead-bismuth alloy to different test temperatures, which are 200° C. to 400° C. respectively.

[0041] The flow meter 34 may be located on the heating pipe 31 at the outlet of the branch heater 32, and is used to measure the flow of the lead-bismuth alloy output from the heating pipe 31. The flow meter 34 may preferably be a Venturi flow meter.

[0042] In order to obtain accurate flow data, the Venturi flowmeter needs to be calibrated before the formal test. To this end, the test device of the utility model can also include a flowmeter calibration barrel 60; the flowmeter calibration barrel 60 is connected between the heating branch 30 and the delivery pipeline 20. The flowmeter calibration barrel can be removed after calibration, or kept in the loop, preferably without affecting the test.

[0043] The test section 40 is connected to the rear end of the heating branch 30 and is connected to the lead-bismuth alloy transported by the heating pipe 31. Since the test temperatures of the lead-bismuth alloys transported by different heating branches 30 are different, the lead-bismuth alloys of different temperatures are mixed with each other in the test section 40, and then analysis can be performed based on the temperature pulsation phenomenon and thermal stratification phenomenon generated.

[0044] The test section 40 may be a test container or a test pipe or other equipment having a certain internal space and needing to receive fluids at different temperatures.

[0045] The reflux pipeline 50 is connected between the outlet of the test section 40 and the storage tank 10, and returns the lead-bismuth alloy in the test section 40 to the storage tank 10. The reflux pipeline 50 may include a reflux pipe 51 and a cooler 52; the reflux pipe 51 is connected between the outlet of the test section 40 and the storage tank 10, and the cooler 52 is arranged on the reflux pipe 51 to cool the lead-bismuth alloy.

[0046] Corresponding to the cooler 52 , the test device of the present invention may further include a cooling circuit 70 connected to the cooler 52 and providing a cooling source for the cooler 52 as needed.

[0047] Alternatively, the cooling circuit 70 may include a thermal oil tank 71 for storing thermal oil, a thermal oil pump 72, an oil inlet pipe 73, and an oil return pipe 74; the oil inlet pipe 73 is connected between the outlet of the thermal oil tank 71 and the cooler 52, and the oil return pipe 74 is connected between the inlet of the thermal oil tank 71 and the cooler 52, so as to connect the cooler 52 and the thermal oil tank 71 to form a cooling circuit 70. The thermal oil enters the cooler 52 from the thermal oil tank 71 along the oil inlet pipe 73, and after heat exchange with the lead-bismuth alloy passing through the cooler 52, flows back to the thermal oil tank 71 along the oil return pipe 74. The thermal oil pump 72 provides power to drive the thermal oil to circulate in the cooling circuit 70, and may be arranged on the oil inlet pipe 73 or the oil return pipe 74.

[0048] The oil inlet pipeline 73 is also provided with a filter 75 for filtering the heat transfer oil entering the cooler 52 to filter out particles, impurities, etc. therein.

[0049] Furthermore, in the test device of the present invention, the lead-bismuth alloy in the storage tank 10 is first pressed into the delivery pipeline 21 under high pressure, and then the lead-bismuth alloy is pumped into the heating branch 30 through the delivery pump 22 on the delivery pipeline 21. In this regard, the test device of the present invention may also include a high-pressure gas supply unit 80, which applies high pressure to the storage tank 10 through high-pressure gas. That is, the high-pressure gas supply unit 80 is connected to the storage tank 10, and high-pressure argon gas is sent into the storage tank 10 to press the lead-bismuth alloy in the storage tank 10 into the delivery pipeline 20.

[0050] The high-pressure gas supply unit 80 may specifically include a high-pressure gas tank 81 and a gas delivery pipeline 82 connected between the high-pressure gas tank 81 and the storage tank 10. A gas heater 83 is provided on the gas delivery pipeline 82 for heating the argon gas so that the argon gas enters the storage tank 10 after the temperature is increased, so as to prevent the argon gas at room temperature from entering the storage tank 10 and lowering the temperature of the melted lead-bismuth alloy.

[0051] The heating temperature of the gas heater 83 is 200°C to 400°C.

[0052] A pressure gauge 84 is provided on the gas supply pipeline 82 for monitoring the pressure of the argon gas.

[0053] Furthermore, the test device of the utility model may also include an exhaust pipe 11 connected to the storage tank 10, and the exhaust pipe can exhaust the storage tank 10 before the storage tank 10 is loaded with lead and bismuth, before the test after the storage tank 10 is loaded with lead and bismuth, and after the test.

[0054] The exhaust pipe 11 is provided with a filter 12 to filter the exhausted gas to prevent harmful substances, impurities, etc. contained therein from being directly discharged.

[0055] After the test is completed, the high-pressure gas supply unit 80 can also provide argon gas to purge the entire circuit. During the purge, the argon gas is output from the storage tank 10, enters the delivery pipeline 20, the heating branch 30 and the return pipeline 50 in sequence, then returns to the storage tank 10 from the loop pipeline, and is finally discharged from the exhaust pipe 11.

[0056] In combination with the above-mentioned arrangement of the high-pressure gas supply unit 80 and the exhaust pipe 11, the high-pressure gas supply unit 80 can be further connected to the flow meter calibration barrel 60 to provide a purge gas for cleaning the flow meter calibration barrel 60. The high-pressure gas tank 81 can be connected to the flow meter calibration barrel 60 through a gas pipe 85, and the flow meter calibration barrel 60 is also connected to the exhaust pipe 11 through an output pipe 61. After the calibration of the flow meter calibration barrel 60 is completed, argon gas can be sent into the flow meter calibration barrel 60 along the gas pipe 85 through the high-pressure gas tank 81, and the argon gas is then discharged to the exhaust pipe 11 through the output pipe 61, so as to clean the flow meter calibration barrel 60.

[0057] The gas pipeline 85 may also be provided with a heater 86 for heating the argon gas and a pressure gauge 87 for monitoring the pressure.

[0058] In addition, it can be understood that the delivery pipeline 20, heating branch 30, return pipeline 50, high-pressure gas supply unit 80, cooling circuit 70 and exhaust pipeline 11 in the utility model are respectively provided with control valves to control the opening and closing and / or flow of the pipelines in which the valves are located.

[0059] When the sample device of the utility model is used:

[0060] Before the test begins, a lead-bismuth alloy is placed in the storage tank 10 and then sealed tightly; the entire circuit is replaced with argon gas through the high-pressure gas supply unit 80; and heat transfer oil is placed in the heat transfer oil tank 71 and then sealed tightly.

[0061] During the test preparation stage, the lead-bismuth alloy is heated and melted by a heating wire wound around the outside of the storage tank 10, and the lead-bismuth alloy is heated to 200° C. to completely melt the lead-bismuth alloy; the high-pressure gas supply unit 80 is turned on, and the lead-bismuth alloy is pressed into the conveying pipe 21 with high-pressure argon gas. After the conveying pipe 21 is filled with the lead-bismuth alloy, the feed pump 22 is turned on; and the heat transfer oil in the heat transfer oil tank 71 is preheated to a specified operating temperature.

[0062] During the test, the lead-bismuth alloy is heated to the specified operating temperature in the branch heaters 32 of the two heating branches 30 respectively, and then enters the test section 40 for mixing to simulate the temperature pulsation and thermal stratification of the lead-bismuth medium, and then is cooled to the specified temperature through the cooler 52; the flow rate of the heat transfer oil is controlled by the valve on the cooling circuit 70 to achieve different cooling boundaries.

[0063] At the end of the test, the feed pump 22 is turned off, the inlet valve of the storage tank 10 is opened, and the material in the loop flows into the storage tank 10 through the liquid level difference, and the remaining material is blown into the storage tank 10 with argon gas. The exhaust gas in the loop is filtered by the filter on the exhaust pipe and then discharged to the outdoor high altitude.

[0064] The following further illustrates the test application of the utility model by taking the test section as a pipeline.

[0065] refer to Figure 2 The pipeline includes a main pipe and a secondary pipe connected to the main pipe. One opening of the main pipe is an inlet, an opening of the secondary pipe away from the main pipe is another inlet, and another opening of the main pipe opposite to the main pipe is an outlet.

[0066] The two inlets are respectively connected to the two heating branches to receive the lead-bismuth alloy with different flow rates and temperatures from the two heating branches, wherein the main pipe is 1 m / s and 300°C; the secondary pipe is 0.5 m / s and 350°C.

[0067] Lead-bismuth alloy is mixed in the rear end of the main pipe. D represents the diameter of the main pipe, and four measuring points are selected on the rear end of the main pipe, which are located at 0.5D, 1D, 2D and 4D respectively. The temperature pulsation data of the four measuring points are shown in Table 1, and the flow velocity pulsation data are shown in Table 2.

[0068] Table 1

[0069]

[0070]

[0071] The curve corresponding to the data in Table 1 is as follows Figure 3 As shown, point 1, point 2, point 3 and point 4 and their corresponding curves are the curves corresponding to measuring points 1 to 4 respectively.

[0072] Table 2

[0073]

[0074]

[0075] The curve corresponding to the data in Table 2 is as follows Figure 4 As shown in the figure, points 1, 2, 3 and 4 and their corresponding curves are the curves corresponding to measuring points 1 to 4 respectively; the flow velocities of measuring points 3 and 4 changing with time are basically the same. Figure 4 The curves corresponding to midpoint 3 and point 4 basically coincide.

[0076] The above description is only an embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium, characterized in that: It includes a storage tank for storing lead-bismuth alloy, a delivery pipeline, at least two heating branches, a test section and a return pipeline; At least two of the heating branches are arranged in parallel and connected between the delivery pipeline and the test section, and the return pipeline is connected between the test section and the storage tank; The conveying pipeline conveys the lead-bismuth alloy in the storage tank to the two heating branches. Each heating branch heats the lead-bismuth alloy to the test temperature and then conveys it to the test section. The lead-bismuth alloys at different test temperatures are mixed in the test section and then returned to the storage tank through the reflux pipeline.

2. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 1 is characterized in that: Each of the heating branches includes a heating pipe, a branch heater arranged on the heating pipe, a temperature measuring unit and a flow meter.

3. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 2, characterized in that: The temperature measuring unit comprises a branch thermometer, and the branch thermometer is located at the inlet end and / or the outlet end of the branch heater on the heating pipe.

4. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 2, characterized in that: The flow meter is a Venturi flow meter.

5. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 4, characterized in that: The test device also includes a flow meter calibration barrel; the flow meter calibration barrel is connected between the heating branch and the delivery pipeline.

6. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 1, characterized in that: The storage tank is provided with a heating unit for heating and melting the lead-bismuth alloy; the heating unit comprises a heating wire wound around the storage tank.

7. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 1, characterized in that: The delivery pipeline includes a delivery pipeline and a feed pump arranged on the delivery pipeline; The conveying pipeline is also provided with a preheater for heating the lead-bismuth alloy and at least one thermometer; the thermometer is located at the inlet end and / or outlet end of the preheater on the conveying pipeline.

8. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 1, characterized in that: The reflux pipeline includes a reflux pipe and a cooler arranged on the reflux pipe for cooling the lead-bismuth alloy.

9. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 8, characterized in that: The test device also includes a cooling circuit connected to the cooler and providing a cold source for the cooler.

10. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 9, characterized in that: The cooling circuit includes a thermal oil tank for storing thermal oil, a thermal oil pump, an oil inlet pipeline and an oil return pipeline; the oil inlet pipeline is connected between the outlet of the thermal oil tank and the cooler, and the oil return pipeline is connected between the inlet of the thermal oil tank and the cooler; The heat transfer oil pump is arranged on the oil inlet pipeline or the oil return pipeline.

11. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to any one of claims 1 to 10, characterized in that: The test device also includes a high-pressure gas providing unit; The high-pressure gas supply unit is connected to the storage tank and delivers high-pressure gas into the storage tank to press the lead-bismuth alloy in the storage tank into the delivery pipeline; The high-pressure gas supply unit includes a high-pressure gas tank and a gas delivery pipeline connected between the high-pressure gas tank and a storage tank.

12. The test device for simulating temperature pulsation and thermal stratification of lead-bismuth medium according to claim 11, characterized in that: A gas heater and a pressure gauge are provided on the gas supply pipeline.

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