Test method of heat pipe for heat pipe micro-reactor

Abstract

The invention provides a test method of a heat pipe for a heat pipe micro-stack. The test method comprises the following steps: sequentially carrying out a high-temperature aging test, an irradiation aging test, an earthquake test and an accident test on a to-be-tested heat pipe for the heat pipe micro-stack; the temperature of the high-temperature aging test is 800-900 DEG C. The test method is reasonable in design and simple in test process, whether the performance of the heat pipe for the heat pipe micro-reactor reaches the standard or not after being subjected to various different conditions is truly and reasonably tested, and development of related technologies of the heat pipe micro-reactor is promoted.

Description

Technical Field

[0001] This invention relates to the field of nuclear power technology, and in particular to a test method for a heat pipe used in a heat pipe microreactor. Background Technology

[0002] The miniaturization of nuclear power reactors facilitates the flexible use of nuclear energy in various application scenarios. Heat pipe microreactors, as a typical type of microreactor, possess excellent inherent safety and represent an important development direction for future nuclear energy and even the broader energy sector. The outstanding performance of heat pipe microreactors in terms of safety, flexibility, and reliability has garnered significant attention in areas such as deep space exploration, deep-sea exploration, and onshore mobile power sources.

[0003] As a crucial core component of the heat pipe microreactor, the heat pipe is the reactor's sole heat transfer element. It is required to perform its safety-related functions under normal, abnormal, and accident conditions to ensure the intrinsic safety of the heat pipe microreactor; its importance is self-evident. Therefore, the heat pipe must undergo a series of rigorous evaluations before formal commissioning to ensure that the equipment can reliably perform its safety functions under normal and accident conditions.

[0004] CN118098655A discloses a heat pipe microreactor simulation electric heating rod, comprising a shell and a heating assembly. The shell includes a titanium alloy outer shell and a stainless steel inner shell. The heating assembly includes a heating wire and a core. The heating wire is circumferentially wound around the core and non-uniformly distributed along the core's axial direction. The core is nested within the inner shell, with the heating wire abutting against the inner surface of the inner shell. This heat pipe microreactor simulation electric heating rod can continuously simulate the high-temperature heating state of a heat pipe microreactor fuel rod with non-uniform power distribution along the axial direction, optimizing the design and verification of heat pipe microreactors.

[0005] CN117766164A discloses a micro-pile cooling device using loop heat pipes. The micro-pile cooling device includes multiple loop heat pipe evaporation module units, which are respectively located in the condensation section of each heat pipe. Each loop heat pipe evaporation module unit includes: a capillary wick sleeved outside the condensation section of each heat pipe, with the primary wick of the capillary wick directly wrapping the heat pipe and the secondary wick wrapping the outside of the primary wick; a liquid channel located on the outer periphery of each heat pipe, connected to a liquid supply device and passing through the capillary wick, through which the liquid in the liquid channel enters the interior of the primary wick and contacts the heat pipe via the wicking action of the capillary wick; and an evaporation chamber located outside each capillary wick for collecting the gas generated after the liquid evaporates due to heating.

[0006] CN118936171A discloses a heat exchanger for a heat pipe micro-stacking system, including a heat exchanger shell and an outer sleeve disposed within the heat exchanger shell. A heat pipe is inserted inside the outer sleeve, and a first protrusion is provided inside the outer sleeve. The inner diameter of the first protrusion matches the outer diameter of the heat pipe, which can both support the heat pipe and form a medium flow channel between the outer sleeve and the heat pipe. The medium exchanges heat with the heat pipe through this flow channel, improving heat exchange efficiency. Furthermore, the medium flows axially within the flow channel, effectively avoiding tube bundle vibration and ensuring heat pipe safety. Simultaneously, the cold medium contacts the outer sleeve first after entering the heat exchanger shell, preventing the cold medium from directly impacting the heat pipe and preventing rapid temperature drop and failure of the heat pipe, thus improving heat pipe reliability.

[0007] However, none of the aforementioned heat pipe micropile patent technologies disclose how to test the heat pipes used in the heat pipe micropile to ensure that the heat pipes perform normally before formal operation, thereby meeting actual usage requirements. Summary of the Invention

[0008] In view of the problems existing in the prior art, the present invention provides a test method for heat pipes used in heat pipe micro-stacking. By subjecting the heat pipes to be tested in the heat pipe micro-stacking in sequence to high-temperature aging test, irradiation aging test, earthquake test and accident test, the heat pipe performance is ensured to be good and able to meet the needs of normal use.

[0009] To achieve this objective, the present invention adopts the following technical solution:

[0010] This invention provides a test method for heat pipes used in heat pipe microreactors. The test method includes sequentially conducting high-temperature aging tests, irradiation aging tests, earthquake tests, and accident tests on the heat pipes used in the heat pipe microreactors to be tested. The high-temperature aging test temperature is 800-900℃.

[0011] The test method for heat pipes used in heat pipe microreactors described in this invention fully considers various environmental factors that may affect the operation of heat pipes, including high-temperature aging, irradiation aging, vibration aging, impact, earthquakes, and accidents, based on the structural characteristics, installation method, safety functions, design parameters, and actual application conditions of the heat pipes. According to the actual application conditions of the heat pipes, high-temperature aging tests, irradiation aging tests, earthquake tests, and accident tests are carried out in sequence to test whether the performance of the heat pipes is qualified and meets the actual use requirements under real heat pipe microreactor operation conditions, thus promoting the development of heat pipe microreactor technology.

[0012] The high-temperature aging test temperature described in this invention is 800-900℃, for example, it can be 800℃, 820℃, 850℃, 870℃, 890℃ or 900℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0013] This invention has conducted extensive literature review and found that the temperature range of the heat pipe for heat pipe micro stack under normal operating conditions is 800-900℃. Therefore, a long-term aging test was carried out within this temperature range, and a liquid penetration test was conducted on the weld position of the heat pipe after the test to determine whether the high-temperature anti-aging performance of the heat pipe meets the standard.

[0014] Preferably, the heat pipe used in the heat pipe microreactor is made of 316H stainless steel, which contains high levels of Cr and Ni in the matrix, resulting in higher long-term stability at high temperatures and making it more suitable for use in nuclear power microreactors.

[0015] Preferably, the high-temperature aging test includes the following steps:

[0016] The heat pipes of the heat pipe micro-pile to be tested are placed in a high-temperature furnace. The furnace temperature is gradually increased to the high-temperature aging test temperature and maintained for the high-temperature aging test time. After the test, the temperature is lowered to obtain the heat pipe after the high-temperature aging test.

[0017] Preferably, the high-temperature aging test time is 2013 to 8476 hours, for example, it can be 2013 hours, 3500 hours, 5024 hours, 6789 hours, 7900 hours or 8476 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0018] The preferred high-temperature aging test time of the present invention is 2013 to 8476 hours. This time fully considers the time range during which the heat pipe can maintain the yield strength required for use under normal service temperature conditions.

[0019] Preferably, during the high-temperature aging test, the average heating rate of the high-temperature furnace is controlled to be ≤1℃ / min, for example, it can be 1℃ / min, 0.9℃ / min, 0.7℃ / min, 0.5℃ / min, 0.3℃ / min or 0.1℃ / min, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0020] The average cooling rate is ≤1℃ / min, for example, it can be 1℃ / min, 0.9℃ / min, 0.7℃ / min, 0.5℃ / min, 0.3℃ / min or 0.1℃ / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0021] The high-temperature aging test described in this invention controls the average heating rate and average cooling rate of the high-temperature furnace to match the actual operation of the heat pipe micro-pile, ensuring that the heat pipe that meets the standards after the high-temperature aging test can truly meet the actual use requirements.

[0022] Preferably, the steps of the irradiation aging test include:

[0023] After the high-temperature aging test, the heat pipe was placed in an irradiation device and uniformly irradiated using a neutron irradiation source to obtain the heat pipe after the irradiation aging test.

[0024] Preferably, the cumulative total dose of the neutron irradiation test is ≥5.5 dpa, for example, it can be 5.5 dpa, 5.6 dpa, 5.8 dpa, 6 dpa, 6.3 dpa or 6.5 dpa, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0025] The heat pipe used in the heat pipe micropile of this invention is made of 316H stainless steel, and the effects of gamma radiation and beta radiation on it are almost negligible. Therefore, the main consideration is the effect of neutron irradiation. The change in the microstructure of the heat pipe after neutron irradiation leads to changes in its mechanical properties, primarily an increase in hardness and yield strength, i.e., radiation hardening. The uniformity of irradiation of the test prototype should be ensured during the experiment. The dose rate is measured at the equivalent geometric center line of the irradiated device, with the end of the device as the measurement reference point, measuring the equivalent dose at that location.

[0026] Preferably, the steps of the earthquake test include:

[0027] After the irradiation aging test, the heat pipe was rigidly connected to the seismic test bench, and the operating baseline seismic test and the safe shutdown seismic test were carried out in sequence to obtain the heat pipe after the seismic test.

[0028] Preferably, the number of operational benchmark seismic tests is at least 5, for example, 5, 6, 7 or 8 times.

[0029] Preferably, the operational benchmark seismic test includes simultaneously generating independent artificial simulated seismic waves from three orthogonal directions (x, y, and z) for a duration of ≥30s, such as 30s, 33s, 35s, 40s, 45s, 50s, or 70s, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0030] The vibration frequency of the earthquake test bench is 1 to 100 Hz, for example, it can be 1 Hz, 20 Hz, 45 Hz, 68 Hz, 85 Hz or 100 Hz, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0031] Preferably, the coherence function value between the artificially simulated seismic waves in three orthogonal directions is <0.5, for example, it can be 0.49, 0.47, 0.45, 0.4, 0.3, 0.2 or 0.1, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0032] Or the absolute value of the correlation coefficient is <0.3, for example, it can be 0.29, 0.27, 0.25, 0.23, 0.2 or 0.1, etc., but it is not limited to the listed values. Other unlisted values ​​within this range also apply.

[0033] Preferably, the steps of the accident test include:

[0034] After the earthquake test, the heat pipe was placed in a high-temperature furnace. The furnace temperature was gradually increased to the accident test temperature and maintained for the accident test time. After the test, the temperature was lowered to obtain the heat pipe after the accident test.

[0035] Preferably, the accident test temperature is 800-900℃, for example, it can be 800℃, 820℃, 850℃, 870℃, 890℃ or 900℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0036] Preferably, the accident test time is 2 to 2.5 hours, for example, it can be 2 hours, 2.1 hours, 2.2 hours, 2.3 hours, 2.4 hours or 2.5 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0037] Preferably, during the accident test, the average heating rate of the high-temperature furnace is controlled to be ≤1℃ / min, for example, it can be 1℃ / min, 0.9℃ / min, 0.7℃ / min, 0.5℃ / min, 0.3℃ / min or 0.1℃ / min, etc., but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0038] The average cooling rate is ≤1℃ / min, for example, it can be 1℃ / min, 0.9℃ / min, 0.7℃ / min, 0.5℃ / min, 0.3℃ / min or 0.1℃ / min, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0039] Preferably, liquid penetration tests are performed on the weld seams of the heat pipes after the high-temperature aging test, the irradiation aging test, the earthquake test, and the accident test to check for defects in the heat pipes after each test.

[0040] As a preferred technical solution of the present invention, the test method includes the following steps:

[0041] (1) The heat pipe to be tested for the heat pipe micro-stacking is placed in a high-temperature furnace. The furnace temperature is gradually increased to 800-900℃ at an average heating rate of ≤1℃ / min and then maintained for 2013-8476h. After the test, the temperature is reduced at an average cooling rate of ≤1℃ / min to obtain the heat pipe after the high-temperature aging test. The material of the heat pipe for the heat pipe micro-stacking is 316H stainless steel.

[0042] (2) After the high-temperature aging test, the heat pipe is placed in an irradiation device and uniformly irradiated with a neutron irradiation source to obtain the heat pipe after the irradiation aging test; the cumulative total dose of the neutron irradiation test is ≥5.5 dpa;

[0043] (3) After the irradiation aging test, the heat pipe is rigidly connected to the seismic test bench and subjected to at least 5 operational benchmark seismic tests. Then, a safe shutdown seismic test is conducted to obtain the heat pipe after the seismic test.

[0044] The operational benchmark seismic test includes simultaneously generating independent artificial simulated seismic waves from three orthogonal directions (x, y, and z) for a duration ≥30s, with the vibration frequency of the seismic test bench ranging from 1 to 100Hz; the coherence function value between the artificial simulated seismic waves in the three orthogonal directions is <0.5 or the absolute value of the correlation coefficient is <0.3; the damping ratio of the safe shutdown seismic test is 2% to 7%.

[0045] (4) After the earthquake test, the heat pipe is placed in a high-temperature furnace. The furnace temperature is gradually increased to 800-900℃ at an average heating rate of ≤1℃ / min and then maintained for 2-2.5h. After the test, the heat pipe is cooled down at an average cooling rate of ≤1℃ / min to obtain the heat pipe after the accident test.

[0046] Liquid penetration tests were performed on the weld seams of the heat pipes after the high-temperature aging test, the irradiation aging test, the earthquake test, and the accident test to check for defects in the heat pipes after each test.

[0047] Compared with the prior art, the present invention has at least the following beneficial effects:

[0048] The test method for heat pipes used in heat pipe microreactors provided by this invention is reasonably designed and has a simple test process. By sequentially conducting high-temperature aging tests, irradiation aging tests, earthquake tests, and accident tests on the heat pipes to be tested in the heat pipe microreactors, the performance of the heat pipes is evaluated to see if they meet the actual use requirements, thus promoting the technological development of heat pipe microreactors. Attached Figure Description

[0049] Figure 1 This is a schematic flowchart of the test method for heat pipes used in heat pipe micro-stacking in a specific embodiment of the present invention. Detailed Implementation

[0050] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0051] The present invention will now be described in further detail. However, the examples described below are merely simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0052] As a specific embodiment of the present invention, a test method for heat pipes used in heat pipe micro-stacking is provided, the flowchart of which is shown below. Figure 1 As shown. The test method includes the following steps:

[0053] (1) The heat pipe to be tested for the heat pipe micro-pile is placed in a high-temperature furnace. The furnace temperature is gradually increased to 900℃ at an average heating rate of 0.8℃ / min and then maintained for 5476h. After the test, the temperature is reduced at an average cooling rate of 1℃ / min to obtain the heat pipe after the high-temperature aging test. The material of the heat pipe for the heat pipe micro-pile is 316H stainless steel.

[0054] (2) After the high-temperature aging test, the heat pipe is placed in an irradiation device and uniformly irradiated with a neutron irradiation source to obtain the heat pipe after the irradiation aging test; the cumulative total dose of the neutron irradiation test is 5.5 dpa.

[0055] (3) After the irradiation aging test, the heat pipe is rigidly connected to the seismic test bench. After five operational benchmark seismic tests, a safe shutdown seismic test is conducted to obtain the heat pipe after the seismic test.

[0056] The operational benchmark seismic test includes simultaneously generating independent artificial simulated seismic waves from three orthogonal directions (x, y, and z) for a duration of 30 seconds. The vibration frequency of the seismic test bench is 1–100 Hz. The coherence function value between the artificial simulated seismic waves in the three orthogonal directions is <0.5 or the absolute value of the correlation coefficient is <0.3. The damping ratio of the safe shutdown seismic test is 5%.

[0057] (4) After the earthquake test, the heat pipe was placed in a high-temperature furnace. The furnace temperature was gradually increased to 900℃ at an average heating rate of 1℃ / min and then maintained for 2 hours. After the test, the temperature was reduced at an average cooling rate of 0.5℃ / min to obtain the heat pipe after the accident test.

[0058] Liquid penetration tests were conducted on the weld seams of the heat pipes after high-temperature aging tests, irradiation aging tests, earthquake tests, and accident tests in this specific embodiment. After the tests, the heat pipes after each test were inspected and no defects were found, which proves that the heat pipes used in the heat pipe micro-pile to be tested in this specific embodiment have excellent performance and can meet the actual use requirements.

[0059] In summary, the test method for heat pipes used in heat pipe microreactors provided by this invention tests the performance of heat pipes from aspects such as high-temperature aging, irradiation aging, vibration aging, impact, earthquake and accident to determine whether the heat pipe meets the standards, and thus evaluates whether the heat pipe under test meets the actual use requirements. It is suitable for widespread application in the field of heat pipe microreactors.

[0060] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A test method for heat pipes used in heat pipe micro-stacking, characterized in that, The test method includes sequentially conducting high-temperature aging tests, irradiation aging tests, earthquake tests, and accident tests on the heat pipes of the heat pipe micro-pile to be tested; The high-temperature aging test temperature is 800–900℃.

2. The test method according to claim 1, characterized in that, The heat pipes used in the heat pipe micropile are made of 316H stainless steel.

3. The test method according to claim 1 or 2, characterized in that, The steps of the high-temperature aging test include: The heat pipes of the heat pipe micro-pile to be tested are placed in a high-temperature furnace. The furnace temperature is gradually increased to the high-temperature aging test temperature and maintained for the high-temperature aging test time. After the test, the temperature is lowered to obtain the heat pipe after the high-temperature aging test.

4. The test method according to claim 3, characterized in that, The high-temperature aging test duration was 2013–8476 hours; Preferably, during the high-temperature aging test, the average heating rate of the high-temperature furnace is controlled to be ≤1℃ / min, and the average cooling rate is controlled to be ≤1℃ / min.

5. The test method according to any one of claims 1 to 4, characterized in that, The steps of the irradiation aging test include: After the high-temperature aging test, the heat pipe was placed in an irradiation device and uniformly irradiated using a neutron irradiation source to obtain the heat pipe after the irradiation aging test. Preferably, the cumulative total dose of the neutron irradiation test is ≥5.5 dpa.

6. The test method according to any one of claims 1 to 5, characterized in that, The steps of the earthquake test include: After the irradiation aging test, the heat pipe was rigidly connected to the seismic test bench, and the operating baseline seismic test and the safe shutdown seismic test were carried out in sequence to obtain the heat pipe after the seismic test. Preferably, the number of operational benchmark seismic tests is at least 5. Preferably, the operational benchmark seismic test includes simultaneously generating independent artificial simulated seismic waves from three orthogonal directions (x, y, and z) for a duration of ≥30s, and the vibration frequency of the seismic test bench is 1–100Hz. Preferably, the coherence function value between the artificially simulated seismic waves in three orthogonal directions is <0.5 or the absolute value of the correlation coefficient is <0.3; Preferably, the damping ratio of the safe shutdown seismic test is 2% to 7%.

7. The test method according to any one of claims 1 to 6, characterized in that, The steps of the accident test include: After the earthquake test, the heat pipe was placed in a high-temperature furnace. The furnace temperature was gradually increased to the accident test temperature and maintained for the accident test time. After the test, the temperature was lowered to obtain the heat pipe after the accident test.

8. The test method according to claim 7, characterized in that, The accident test temperature is 800–900℃; Preferably, the accident test lasts for 2 to 2.5 hours; Preferably, during the accident test, the average heating rate of the high-temperature furnace is controlled to be ≤1℃ / min, and the average cooling rate is controlled to be ≤1℃ / min.

9. The test method according to any one of claims 1 to 8, characterized in that, Liquid penetration tests were performed on the weld seams of the heat pipes after the high-temperature aging test, the irradiation aging test, the earthquake test, and the accident test to check for defects in the heat pipes after each test.

10. The test method according to any one of claims 1 to 9, characterized in that, The experimental method includes the following steps: (1) The heat pipe to be tested for the heat pipe micro-stacking is placed in a high-temperature furnace. The furnace temperature is gradually increased to 800-900℃ at an average heating rate of ≤1℃ / min and then maintained for 2013-8476h. After the test, the temperature is reduced at an average cooling rate of ≤1℃ / min to obtain the heat pipe after the high-temperature aging test. The material of the heat pipe for the heat pipe micro-stacking is 316H stainless steel. (2) After the high-temperature aging test, the heat pipe is placed in an irradiation device and uniformly irradiated with a neutron irradiation source to obtain the heat pipe after the irradiation aging test; the cumulative total dose of the neutron irradiation test is ≥5.5 dpa; (3) After the irradiation aging test, the heat pipe is rigidly connected to the seismic test bench and subjected to at least 5 operational benchmark seismic tests. Then, a safe shutdown seismic test is conducted to obtain the heat pipe after the seismic test. The operational benchmark seismic test includes simultaneously generating independent artificial simulated seismic waves from three orthogonal directions (x, y, and z) for a duration ≥30s, with the vibration frequency of the seismic test bench ranging from 1 to 100Hz; the coherence function value between the artificial simulated seismic waves in the three orthogonal directions is <0.5 or the absolute value of the correlation coefficient is <0.3; the damping ratio of the safe shutdown seismic test is 2% to 7%. (4) After the earthquake test, the heat pipe is placed in a high-temperature furnace. The furnace temperature is gradually increased to 800-900℃ at an average heating rate of ≤1℃ / min and then maintained for 2-2.5h. After the test, the heat pipe is cooled down at an average cooling rate of ≤1℃ / min to obtain the heat pipe after the accident test. Liquid penetration tests were performed on the weld seams of the heat pipes after the high-temperature aging test, the irradiation aging test, the earthquake test, and the accident test to check for defects in the heat pipes after each test.

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