Device and test method for verifying the self-blocking behavior of sodium and carbon dioxide reactants
By designing a device for verifying the self-blocking behavior of sodium-carbon dioxide reaction products, using inert gas environment and high-pressure argon detection, the problem of self-blocking behavior of sodium and carbon dioxide reaction products in sodium-cooled fast reactors was solved, and a printed circuit was provided The design basis of plate heat exchangers reduces R&D costs and increases application value.
Patent Information
- Application Number
- CN201910878491.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2019-09-18
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2039-09-18
AI Technical Summary
In sodium-cooled fast reactors, printed circuit board heat exchangers may cause "self-blocking" behavior due to the reaction between sodium and carbon dioxide, resulting in design challenges and safety risks. It is difficult for the prior art to effectively verify whether this reaction product exists and affects the design.
Design a device including an outer cylinder, an upper flange, an intake connection, an outlet connection, an anti-spill chamber, an anti-spill skirt and a reaction sleeve. By dropping metal sodium into the device under an inert gas environment, vacuum treatment is performed , heating and cooling, simulate the reaction between sodium and carbon dioxide, and use high-pressure argon to detect leakage.
This device can effectively verify whether the sodium-carbon dioxide reaction product has "self-blocking", providing a basis for the design of printed circuit board heat exchangers, reducing R&D costs and enhancing application value.
Smart Images
Figure CN110542574B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of heat exchangers in sodium-cooled fast reactors, and in particular to a device and a test method for verifying the self-blocking behavior of sodium and carbon dioxide reactants. Background Art
[0002] In the sodium-cooled fast reactor based on the supercritical carbon dioxide braiding cycle system, the PCB heat exchanger is the main type of heat exchanger. The operating pressure of the supercritical carbon dioxide side of the PCB heat exchanger is about 20MPa and the operating temperature is about 530℃, and the operating pressure of the sodium side is about 0.1MPa and the operating temperature is 550℃. Therefore, when the PCB heat exchanger is in operation, if a micro-leakage occurs, the high-pressure carbon dioxide will inevitably migrate to the sodium and then react with the sodium. Sodium and carbon dioxide will react violently at high temperatures (above 460℃), but the reactants are sodium carbonate, carbon and other particles that are insoluble in sodium, so there is a possibility that the sodium-supercritical carbon dioxide reaction products will produce "self-blocking" behavior in the PCB heat exchanger.
[0003] Therefore, verifying whether the sodium-carbon dioxide reaction products produce "self-blocking" in the printed circuit board type heat exchanger is of great significance to the design of the printed circuit board type heat exchanger and the design of the sodium-cooled fast reactor using the supercritical carbon dioxide Brayton cycle system. Summary of the invention
[0004] In view of the defects existing in the prior art, the purpose of the present invention is to provide a device and a test method for verifying the self-blocking behavior of sodium and carbon dioxide reactants. The device can test whether the sodium-carbon dioxide reaction product produces "self-blocking" in a printed circuit board type heat exchanger, thereby providing a basis for the design of the printed circuit board type heat exchanger (such as the selection of the sodium side pipe diameter, etc.).
[0005] To achieve the above purpose, the technical solution adopted by the present invention is as follows:
[0006] A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants, the device comprising an outer cylinder, an upper flange, an air inlet pipe, an air outlet pipe, an anti-overflow cavity, an anti-overflow skirt, and a reaction sleeve, wherein the upper flange is sealed and fixedly installed on the top surface of the outer cylinder, the air inlet pipe and the air outlet pipe are respectively communicated with the inner cavity of the outer cylinder, the reaction sleeve is arranged in the inner cavity of the outer cylinder, the inner tube of the reaction sleeve is connected to the bottom end of the air inlet pipe through the anti-overflow cavity, and the anti-overflow skirt is arranged on the edges around the top of the outer sleeve in the reaction sleeve.
[0007] Furthermore, the device also includes a support rod, wherein the anti-overflow skirt is fixedly mounted on the edges around the top of the outer sleeve in the reaction sleeve through the support rod.
[0008] Furthermore, the device also includes a temperature measuring thermocouple, wherein the temperature measuring thermocouple is arranged in the thermocouple well of the outer cylinder.
[0009] Furthermore, the temperature measuring thermocouple is arranged at the bottom end of the reaction sleeve.
[0010] Furthermore, one end of the support rod is fixedly connected to the outer end surface of the bottom end of the anti-overflow cavity, and one end of the support rod is connected to the inner end surface of the upper end of the anti-overflow skirt.
[0011] Furthermore, the inner tube diameter of the reaction sleeve and the width of the annular gap between the inner and outer sleeves are the same.
[0012] At the same time, the present invention also provides a test method based on the above-mentioned device for verifying the automatic behavior of the reaction product of sodium and carbon dioxide, and the test method includes the following steps:
[0013] 1) Place the above test device in an inert gas environment, and drip metallic sodium into the annular gap of the reaction sleeve in the above test device; 2) Remove the test device from the inert gas environment, and evacuate the inside of the test device at room temperature; 3) Heat the test device to 150°C so that the sodium flow flows into the inner tube and annular gap of the reaction sleeve; 4) Cool the test device to room temperature so that the sodium is in a solid state; 5) Fill the test device with connected carbon dioxide gas from the inlet pipe and the outlet pipe, and heat the test device to 550°C so that the sodium and carbon dioxide react fully; 6) After the reaction, stop heating, cool the test device to room temperature, and move the test device to an inert gas environment to observe the reaction of sodium and carbon dioxide; 7) Remove the test device, fill the test device with high-pressure argon gas through the inlet pipe, and connect it to the external atmosphere through the outlet pipe; 8) Heat the test device to 550°C, and gradually add high-pressure argon gas into it; 9) Use an argon leak detector at the outlet pipe of the test device to detect whether there is argon leakage.
[0014] Furthermore, in the above steps 2) and 3), sodium is filled into the inner tube and the annular gap of the reaction sleeve by vacuum and heating.
[0015] Furthermore, in the above step 5), carbon dioxide of the same pressure is simultaneously charged into the test device from the inlet pipe and the outlet pipe.
[0016] Furthermore, in the above step 5), when sodium reacts with carbon dioxide, the inlet pipe and the outlet pipe are always in a connected state.
[0017] Compared with the prior art, the beneficial technical effect of the present solution is that the device of the present invention can be used to test whether the sodium-carbon dioxide reaction product produces "self-blocking" in the printed circuit board type heat exchanger. The test results will be used in the design of the printed circuit board type heat exchanger, providing a basis for the selection of the sodium side pipe diameter of the printed circuit board type heat exchanger, thereby reducing the research and development cost of the printed circuit board type heat exchanger and improving the application value of the printed circuit board type heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Figure 1 It is a schematic diagram of the principle structure of the device used to verify the self-blocking behavior of the reaction product of sodium and carbon dioxide in the present invention.
[0019] In the figure:
[0020] 1-upper flange, 2-air inlet pipe, 3-air outlet pipe, 4-anti-overflow cavity, 5-support rod, 6-anti-overflow skirt, 7-reaction sleeve, 8-outer cylinder, 9-temperature measuring thermocouple. DETAILED DESCRIPTION
[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation methods.
[0022] This scheme is aimed at the fact that sodium and carbon dioxide will produce violent reactions at high temperatures (above 460°C), but the reactants are sodium carbonate, carbon and other particles that are insoluble in sodium. There is a possibility that the sodium-supercritical carbon dioxide reaction product will produce "self-blocking" behavior in the printed circuit board type heat exchanger. Therefore, a device for verifying the self-blocking behavior of the reaction product of sodium and carbon dioxide is proposed. The device can test whether the sodium-carbon dioxide reaction product produces "self-blocking" in the printed circuit board type heat exchanger, providing a basis for the selection of the sodium side pipe diameter of the printed circuit board type heat exchanger.
[0023] See attached Figure 1As shown, the device for verifying the self-blocking behavior of the reaction product of sodium and carbon dioxide in this embodiment includes an outer cylinder 8 made of stainless steel, a support rod 5, an upper flange 1, an air inlet pipe 2, an air outlet pipe 3, an anti-overflow cavity 4, an anti-overflow skirt 6, a reaction sleeve 7 and a temperature measuring thermocouple 9, wherein the upper flange 1 is sealed and fixedly installed on the top surface of the outer cylinder 8, the air inlet pipe 2 and the air outlet pipe 3 are respectively vertically arranged in the inner cavity of the outer cylinder 8, and the reaction sleeve 7 is vertically arranged in the inner cavity of the outer cylinder 8 and It is connected to the bottom end of the air inlet pipe 2 through the anti-overflow cavity 4, the anti-overflow skirt 6 is arranged on the edges around the top of the outer sleeve in the reaction sleeve 7, the temperature measuring thermocouple 9 is arranged in the inner cavity of the outer cylinder 8, the air inlet pipe 2 is connected to the inner tube of the reaction sleeve 7 through the anti-overflow cavity 4, and the anti-overflow skirt 6 is fixedly installed on the edges around the top of the outer sleeve in the reaction sleeve 7 through the support rod 5, that is, the upper end of the support rod 5 is fixedly connected to the outer end face of the bottom end of the anti-overflow cavity 4, and the bottom end is connected to the inner end face of the upper end of the anti-overflow skirt 6. The outer cylinder 8 is used to protect the sodium from being polluted by the air during the transfer and reaction process, and the upper flange 1 is used to seal the upper end surface of the outer cylinder 8; the air inlet pipe 2 is used to provide inert gas and carbon dioxide that reacts with sodium to the reaction sleeve 7. After the sodium reacts with the carbon dioxide, it can also be used to provide high-pressure gas to the inner cavity of the outer cylinder 8 to test the pressure resistance of the reaction product; the air outlet pipe 3 is used for vacuuming, air intake and exhaust, etc. during the experiment; the anti-overflow cavity 4 is used to prevent sodium from entering the air inlet pipe 2; the support rod 5 is used to support the anti-overflow skirt 6 and ensure the annular gap width of the reaction sleeve 7; the anti-overflow skirt 6 is used to prevent sodium from flowing into the inner cavity of the outer cylinder 8; the reaction sleeve 7 provides a reaction area for the reaction of sodium and carbon dioxide; the temperature measuring thermocouple 9 is used to measure the temperature of the reaction sleeve 7. It should be noted here that the anti-overflow cavity and the air inlet pipe in this embodiment form a thinner tubular structure. After the test starts, the reaction products are deposited in the thin tube and the annular gap, and the high-pressure gas (pressure above 10MPa) input from the air inlet pipe pushes the reaction products. During the pushing process, since the inner cavity volume of the outer cylinder is larger and the air outlet pipe is connected to the external atmosphere, the pressure borne by the outer cylinder is actually smaller. Therefore, the design pressure resistance value of the outer cylinder can be relatively small (0.1MPa is sufficient), so the entire device can greatly reduce the mass of the test container.
[0024] When conducting the test, firstly, the inlet pipe 2 and the outlet pipe 3 of the above-mentioned device in this scheme are connected to valves, and then placed in an inert gas glove box; in the inert gas glove box, use a dropper to fill 10g of metallic sodium into the annular gap of the reaction sleeve 7 along the anti-overflow skirt 6 as much as possible, then assemble the device and move it out of the glove box, and connect it to a laboratory bench that can be evacuated, inflated and heated; at room temperature, the inside and outside of the device are evacuated to a vacuum state (below 10Mpa) from the inlet pipe 2 and the outlet pipe 3; thereafter, the device is heated to 150°C to allow sodium to flow into the inner tube and the annular gap of the reaction sleeve 7 (the sodium pressure inside and outside is in a balanced state); the device is cooled to room temperature to make the sodium in a solid state; 0.5Mpa of carbon dioxide gas is flushed into the device from the inlet pipe 2 and the outlet pipe 3, in order to To ensure that when carbon dioxide reacts with sodium, liquid sodium will not be pressed out due to the pressure difference on both sides, the same pressure of carbon dioxide is filled into the device from the inlet pipe and the outlet pipe, and during the reaction of carbon dioxide and sodium, the inlet pipe and the outlet pipe are always in a connected state; the device is heated to 550°C again to allow sodium and carbon dioxide to fully react for 10 minutes; after the reaction time is reached, the heating is stopped and cooled to room temperature, the device is cooled to room temperature and moved to the glove box, and the reaction is checked in the inert gas glove box to confirm the reaction of sodium and carbon dioxide; the device is reinstalled, high-pressure argon is connected to the inlet pipe 2, and the outlet pipe 3 is connected to the atmosphere; the device is heated to 550°C, and then argon is added to the buffer tank and the pressure is gradually increased (starting from 0.1Mpa). After each pressure increase, an argon leak detector is used at the outlet pipe 3 to monitor whether there is argon leakage. If there is leakage, it means that the sodium and carbon dioxide reaction device cannot withstand the pressure, that is, it cannot maintain "self-blocking" under this pressure.
[0025] In summary, by using the device of the present invention to test whether the sodium-carbon dioxide reaction product produces "self-blocking" in the printed circuit board type heat exchanger, the results of the test will be used in the design of the printed circuit board type heat exchanger, providing a basis for the selection of the sodium side pipe diameter of the printed circuit board type heat exchanger, thereby reducing the research and development cost of the printed circuit board type heat exchanger and improving the application value of the printed circuit board type heat exchanger.
[0026] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.
Claims
1. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants, characterized in that: The device comprises an outer cylinder, an upper flange, an air inlet pipe, an air outlet pipe, an anti-overflow cavity, an anti-overflow skirt, and a reaction sleeve, wherein the upper flange is sealed and fixedly mounted on the top surface of the outer cylinder, the air inlet pipe and the air outlet pipe are respectively connected with the inner cavity of the outer cylinder, the air inlet pipe is used to provide inert gas and carbon dioxide that reacts with sodium to the reaction sleeve, the reaction sleeve is arranged in the inner cavity of the outer cylinder, and is used to provide a reaction area for the reaction of sodium and carbon dioxide, the inner tube of the reaction sleeve is connected to the bottom end of the air inlet pipe through the anti-overflow cavity, the anti-overflow cavity is used to prevent sodium from entering the air inlet pipe, the anti-overflow skirt is arranged on the edges around the top of the outer sleeve in the reaction sleeve, and is used to prevent sodium from flowing into the inner cavity of the outer cylinder, and metallic sodium is filled into the annular gap of the reaction sleeve along the anti-overflow skirt.
2. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants according to claim 1, characterized in that: The device also includes a support rod, wherein the anti-overflow skirt is fixedly mounted on the edges around the top of the outer sleeve in the reaction sleeve through the support rod.
3. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants according to claim 1 or 2, characterized in that: The device also includes a temperature measuring thermocouple, wherein the temperature measuring thermocouple is arranged in the thermocouple well of the outer cylinder.
4. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants according to claim 3, characterized in that: The temperature measuring thermocouple is arranged at the bottom end of the reaction sleeve.
5. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants according to claim 2, characterized in that: One end of the support rod is fixedly connected to the outer end surface of the bottom end of the anti-overflow cavity, and the other end of the support rod is connected to the inner end surface of the upper end of the anti-overflow skirt.
6. A device for verifying the self-blocking behavior of sodium and carbon dioxide reactants according to claim 1, characterized in that: The inner tube diameter of the reaction sleeve is the same as the annular gap width between the inner tube and the outer sleeve.
7. A test method for verifying the self-blocking behavior of the reaction product of sodium and carbon dioxide using the device according to any one of claims 1 to 6, characterized in that: The test method includes the following steps: 1) placing the device in an inert gas environment and dripping metallic sodium into the annular gap of the reaction sleeve in the device; 2) Remove the device from the inert gas environment and evacuate the interior of the device to a vacuum state at room temperature; 3) heating the device to 150° C. so that the sodium flows into the inner tube and annular gap of the reaction sleeve; 4) Cooling the device to room temperature so that the sodium is in a solid state; 5) Filling the device with connected carbon dioxide gas from the inlet pipe and the outlet pipe, and heating the device to 550° C. to allow sodium to react fully with carbon dioxide; 6) After the reaction, stop heating, cool the device to room temperature, and move the device to an inert gas environment to observe the reaction of sodium and carbon dioxide; 7) Remove the device, fill the device with high-pressure argon gas through the inlet pipe, and connect it to the outside atmosphere through the outlet pipe; 8) heating the device to 550°C and gradually adding high-pressure argon gas therein; 9) Use an argon leak detector to detect whether there is argon leakage at the outlet pipe of the device.
8. The test method according to claim 7, characterized in that: In the above steps 2) and 3), sodium is completely filled into the inner tube and annular gap of the reaction sleeve by vacuum and heating.
9. The test method according to claim 7 or 8, characterized in that: In the above step 5), carbon dioxide of the same pressure is simultaneously charged into the device from the inlet pipe and the outlet pipe.
10. The test method according to claim 7 or 8, characterized in that: In the above step 5), when sodium reacts with carbon dioxide, the inlet pipe and the outlet pipe are always in a connected state.