A test method for operation of a flow restrictor for a high temperature reactor fuel handling system

Abstract

The application discloses a kind of test methods for the operation of high temperature reactor fuel handling system choke, including outlet ball disturbance test and inlet ball disturbance test, by building test bench, build choke in test bench, gas is supplied to choke outlet pipeline, choke executes ball sending action, place multiple graphite ball elements at the inlet of choke, start choke and transport multiple graphite ball elements to downstream pipeline of choke, graphite ball element rolls during transport, graphite ball element rolls smoothly to downstream pipeline and emits sound, if each graphite ball element emits sound when rolling to downstream pipeline, then judge multiple graphite ball elements all roll smoothly to downstream pipeline.The application can verify whether choke can run smoothly, set multiple graphite ball elements to verify test, can improve verification structure accuracy, ensure that the choke verified can run continuously and stably, to guide choke factory acceptance work, so as to improve the availability of choke.

Description

Technical Field

[0001] This invention relates to the field of high-temperature gas-cooled reactor equipment commissioning technology, specifically to a test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system. Background Technology

[0002] During startup and operation, the pebble bed core of the high-temperature gas-cooled reactor generates process heat through a neutron chain reaction. The main helium blower drives the high-pressure helium in the primary loop to circulate repeatedly, carrying away the process heat generated by the chain reaction in the pebble bed core and transferring the heat to the secondary loop to generate high-pressure steam, which drives the turbine generator set to generate electricity.

[0003] Under operating conditions, the fuel loading and unloading system is connected to the pressure vessel to unload fuel elements from the pebble bed core, perform tasks such as fragment separation and burnup measurement, and return spherical elements that have not reached burnup depth to the primary circuit pebble bed, completing the entire non-stop reactor cycle. The burnup loading and unloading system plays an important role in compensating for remaining reactivity in the pebble bed core and in leveling the temperature field of the pebble bed.

[0004] To effectively remove nuclear process heat from the primary coolant core, the main helium blower drives high-pressure circulation of helium from the primary coolant core. Under rated operating conditions, the pressure rise of the main helium blower reaches 200 kPa, and the mass flow rate is 96 kg / s. The fuel loading and unloading system is directly connected to the primary coolant core. Without effective atmosphere isolation, the primary coolant helium will circulate in reverse within the fuel loading and unloading system. This reverse circulation will have two negative effects on the primary coolant core: First, the inner diameter of the spherical flow pipe in the fuel loading and unloading system is 65 mm. If the primary coolant helium circulates in reverse here, the flow rate of helium entering the pebble bed core to carry the process heat of the fuel elements will decrease. This condition will lead to an inability to dissipate core heat, resulting in a rise in fuel temperature. Once the temperature exceeds 1620°C, it will threaten the structural safety of the fuel. Second, when the primary coolant helium circulates in reverse within the fuel loading and unloading system, the gas circulation direction is opposite to the fuel circulation direction. A single spherical element with a mass of 200 g, which relies on gravity for flow, cannot flow normally under the reverse blowing of helium at a pressure of 200 kPa. This operating condition will result in the loss of the high-temperature reactor's ability to continuously refuel.

[0005] To address the aforementioned issues, flow barriers are typically installed in fuel loading and unloading systems. Their function is to isolate the fuel loading and unloading system from the primary loop, preventing reverse circulation of helium from the primary loop within the fuel loading and unloading system. However, when the flow barrier's operating parameters do not match the operating environment, problems such as poor ball delivery by the flow barrier and reverse flow of stored balls upstream of the flow barrier can occur, hindering the stable operation of the fuel loading and unloading system. Summary of the Invention

[0006] Therefore, the present invention aims to solve the problems in the prior art of flow restrictors used in high-temperature gas-cooled reactor loading and unloading systems, which are easily affected by operating parameters and operating environment, resulting in poor ball delivery and reverse flow of upstream balls, affecting equipment acceptance. Thus, the present invention provides a test method for the operation of flow restrictors in high-temperature reactor fuel loading and unloading systems.

[0007] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0008] A test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system includes an outlet sphere disturbance test and an inlet sphere disturbance test, wherein the outlet sphere disturbance test includes the following steps: A1: Construct a test bench and install a flow restrictor inside the test bench; A2: Set up the driver and enter the choke operation program from step A1 into the driver; A3: Power on the current blocker and the driver; A4: Supply gas to the outlet pipe of the flow restrictor, the flow restrictor performs the ball feeding action, place multiple graphite ball elements at the inlet of the flow restrictor, and start the flow restrictor to deliver multiple graphite ball elements to the downstream pipe of the flow restrictor. A5: The graphite ball elements roll during the conveying process. When the graphite ball elements roll smoothly to the downstream pipe, they will make a sound. If each graphite ball element makes a sound when it rolls to the downstream pipe, it is determined that multiple graphite ball elements have rolled smoothly into the downstream pipe. If the number of sounds is less than the number of graphite ball elements that enter the flow restrictor, it is determined that not all graphite ball elements have rolled smoothly into the downstream pipe. The inlet sphere disturbance test includes the following steps: B1: Construct a test bench and install a flow restrictor inside the test bench; B2: Set up the driver and enter the choke operation program from step A1 into the driver; B3: Power on the choke and driver; B4: Supply gas to the outlet pipe of the flow restrictor, the flow restrictor performs the ball feeding action, at least three graphite ball elements are placed at the outlet of the flow restrictor, and the flow restrictor is started to deliver the three graphite ball elements to the downstream pipe of the flow restrictor. B5: Transport a graphite ball element to the downstream pipeline for the flow restrictor ball removal operation; B6: Add one graphite ball element upstream of the flow stopper to restore the number of balls stored upstream of the flow stopper to 3; Repeat steps B4 and B5 in sequence to ensure that each graphite ball element can roll smoothly from the upstream pipe to the downstream pipe.

[0009] Furthermore, in steps A1 and B1, the outlet pressure of the flow restrictor is set to be greater than the inlet pressure, and the pressure difference between the outlet and inlet of the flow restrictor is set to 200 kPa.

[0010] Furthermore, in steps A1 and B1, the angle at which the flow restrictor is set needs to be tilted by 20° so that the inlet end of the flow restrictor is facing upwards.

[0011] Furthermore, in both steps A1 and B1, the test bench needs to be assembled under atmospheric conditions.

[0012] Furthermore, in steps A4 and B4, when the flow restrictor performs the ball feeding action, it needs to be performed under a differential pressure operating environment of 200 kPa.

[0013] Furthermore, in step B6, the movement status of the two graphite ball elements stored upstream needs to be visually inspected during the ball retrieval process.

[0014] Furthermore, in step B6, when repeating step B5, it is necessary to visually inspect the disturbance to the upstream temporary graphite ball element when the flow restrictor performs the ball-taking operation under differential pressure conditions.

[0015] Furthermore, when the flow restrictor performs the ball-retrieving operation, the disturbance to the graphite ball element temporarily stored in the upstream pipe of the flow restrictor can be restored to stillness within 3 seconds, which is an acceptable standard.

[0016] Furthermore, the test bench includes a support block, a flow obstructor obliquely arranged on the support block, a flow ball tube arranged on the flow obstructor, a flow obstructor arranged on the flow ball tube, and an air supply pipe connected to the flow ball tube; the air inlet of the air supply pipe is equipped with a Roots blower, the air outlet of the air supply pipe is connected to the flow ball tube, a pressure reducing valve is provided at one end of the air supply pipe near the flow ball tube, and a buffer tank is provided between the Roots blower and the pressure reducing valve.

[0017] Furthermore, the support block is a wedge-shaped block with an inclined surface, and the flow obstructor is disposed on the inclined surface of the wedge-shaped block, the inclined surface having an inclination angle of 20°.

[0018] The technical solution of this invention has the following advantages: 1. The test method for the operation of the flow restrictor in the fuel loading and unloading system of high-temperature reactors provided by the present invention uses a test bench to test the operating conditions of the flow restrictor, verifying whether the flow restrictor can operate stably. Multiple graphite ball elements are set for verification tests, which can improve the accuracy of the verification structure and ensure that the flow restrictor that passes the verification can operate continuously and stably. This guides the factory acceptance of the flow restrictor, thereby improving the availability of the flow restrictor.

[0019] 2. The test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system provided by this invention, in steps A1 and B1, sets the outlet pressure of the flow restrictor to be greater than the inlet pressure, and sets the pressure difference between the outlet and inlet of the flow restrictor to 200 kPa. With this setting, under conditions of high outlet pressure, when the flow restrictor performs the ball-receiving action, if the rotor speed slows down, the high-pressure gas inside the ball cup is not fully released. After the ball cup reaches its position, the high-pressure gas will have a reverse impact on the upstream stored balls of the flow restrictor, causing the graphite ball elements to move upwards in reverse. When the flow restrictor rotor performs the ball-receiving action and the rotor speed slows down, it will affect the operating efficiency of the flow restrictor and restrict the unit's refueling capacity. This allows for the exploration of the critical ball-receiving speed of the flow restrictor through a test bench, verifying at what speed the operation of the ball cup will not disturb the upstream stored balls while ensuring the operating efficiency of the flow restrictor, thereby ensuring the subsequent stable operation of the flow restrictor.

[0020] 3. The test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system provided by the present invention requires that, in steps A1 and B1, the flow restrictor be tilted at an angle of 20° so that the inlet end of the flow restrictor faces upward. This tilted flow restrictor with the inlet facing upward reduces the ball feeding pressure of the flow restrictor, thereby reducing damage to the coupling caused by long-term, high-frequency ball feeding operations.

[0021] 4. In the test method for the operation of the flow restrictor in the fuel loading and unloading system of a high-temperature reactor provided by the present invention, the test bench needs to be constructed under air atmosphere conditions in both steps A1 and B1. This setup eliminates the need to maintain a high-pressure environment on the test bench, reducing equipment testing investment and operating energy consumption, while also lowering test risks and improving test safety. Attached Figure Description

[0022] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the structure of the test bench in this invention; Explanation of reference numerals in the attached diagram: 1. Flow restrictor; 2. Pressure reducing valve; 3. Buffer tank; 4. Roots blower; 5. Support block. Detailed Implementation

[0024] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0026] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0027] Furthermore, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0028] like Figure 1 The method shown is a test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system, including an outlet ball disturbance test and an inlet ball disturbance test. The outlet ball disturbance test includes the following steps: A1: Construct a test bench and install a flow restrictor inside the test bench; A2: Set up the driver and enter the choke operation program from step A1 into the driver; A3: Power on the current blocker and the driver; A4: Supply air to the outlet pipe of the flow restrictor. The flow restrictor performs the ball feeding action. Place 3 graphite ball elements at the inlet of the flow restrictor. Start the flow restrictor to deliver the 3 graphite ball elements to the downstream pipe of the flow restrictor. The graphite ball elements need to be delivered one by one for verification. A5: The graphite ball elements roll during the conveying process. When the graphite ball elements roll smoothly to the downstream pipe, they will make a sound. If each graphite ball element makes a sound when it rolls to the downstream pipe, it is determined that multiple graphite ball elements have rolled smoothly into the downstream pipe. If the number of sounds is less than the number of graphite ball elements that enter the flow restrictor, it is determined that not all graphite ball elements have rolled smoothly into the downstream pipe. The inlet ball disturbance test includes the following steps: B1: Construct a test bench and install a flow restrictor inside the test bench; B2: Set up the driver and enter the choke operation program from step A1 into the driver; B3: Power on the choke and driver; B4: Supply gas to the outlet pipe of the flow restrictor, the flow restrictor performs the ball feeding action, at least three graphite ball elements are placed at the outlet of the flow restrictor, and the flow restrictor is started to deliver the three graphite ball elements to the downstream pipe of the flow restrictor. B5: Transport a graphite ball element to the downstream pipeline for the flow restrictor ball removal operation; B6: Add one graphite ball element upstream of the flow stopper to restore the number of balls stored upstream of the flow stopper to 3; Repeat steps B4 and B5 in sequence to ensure that each graphite ball element can roll smoothly from the upstream pipe to the downstream pipe.

[0029] This test method for the operation of flow arresters in high-temperature reactor fuel loading and unloading systems uses a test bench to test the flow arrester's operating conditions and verify whether the flow arrester can operate stably. Setting up three graphite ball elements for verification testing can improve the accuracy of the verification structure and ensure that the flow arrester that passes the verification can operate continuously and stably. This guides the flow arrester's factory acceptance process and improves the flow arrester's availability.

[0030] In steps A1 and B1, the outlet pressure of the flow restrictor is set to be greater than the inlet pressure, and the pressure difference between the outlet and inlet is set to 200 kPa. With this setting, under conditions of high outlet pressure, when the flow restrictor performs the ball-receiving action, the rotor speed slows down, and the high-pressure gas inside the ball cup is not fully released. After the ball cup reaches its position, the high-pressure gas will have a reverse impact on the upstream stored balls of the flow restrictor, causing the graphite ball elements to rise in reverse. When the flow restrictor rotor performs the ball-receiving action and the rotor speed slows down, it will affect the operating efficiency of the flow restrictor and restrict the unit's refueling capacity. This allows for the determination of the critical ball-receiving speed of the flow restrictor through a test bench, verifying at what speed the ball cup operation will not disturb the upstream stored balls while ensuring the operating efficiency of the flow restrictor, thus guaranteeing the subsequent stable operation of the flow restrictor.

[0031] In steps A1 and B1, the flow restrictor needs to be tilted at a 20° angle so that its inlet end faces upwards. This tilted flow restrictor with its inlet facing upwards reduces the ball feeding pressure of the flow restrictor, thereby reducing damage to the coupling caused by long-term high-frequency ball feeding.

[0032] In both steps A1 and B1, the test bench must be assembled under atmospheric conditions. This setup eliminates the need to maintain a high-pressure environment on the test bench, reducing equipment testing investment and operating energy consumption, while also lowering testing risks and improving testing safety.

[0033] In steps A4 and B4, the flow restrictor needs to perform the ball feeding action under a differential pressure environment of 200 kPa.

[0034] In step A5, 30 test graphite ball elements are transported to the downstream pipeline of the test bench, and the smoothness of the graphite element flow is judged by whether all the graphite ball elements make a falling sound.

[0035] In step B6, the movement status of the two graphite ball elements stored upstream needs to be visually inspected during the ball retrieval process.

[0036] In step B6, when repeating step B5, a visual inspection is required to check the disturbance to the upstream temporary graphite ball element caused by the flow restrictor during ball removal operation under differential pressure conditions. Steps B4 and B5 should also be repeated sequentially using 30 test graphite ball elements to ensure that each graphite ball element can smoothly roll from the upstream pipe to the downstream pipe.

[0037] When the flow restrictor is performing a ball-retrieving operation, the disturbance to the graphite ball element temporarily stored in the upstream pipe of the flow restrictor can be restored to stillness within 3 seconds, which is an acceptable standard.

[0038] In this embodiment, as Figure 1 As shown, the test bench includes a support block 5, a flow deflector 1 obliquely mounted on the support block 5, a flow tube mounted on the flow deflector 1, a flow deflector 1 mounted on the flow tube, and an air supply pipe connected to the flow tube. A Roots blower 4 is installed at the air inlet of the air supply pipe, and the air outlet of the air supply pipe is connected to the flow tube. A pressure reducing valve 2 is installed at the end of the air supply pipe near the flow tube, and a buffer tank 3 is installed between the Roots blower 4 and the pressure reducing valve 2. Specifically, the support block 5 is a wedge-shaped block with an inclined surface, and the flow deflector 1 is mounted on the inclined surface of the wedge-shaped block, with the inclined surface having an inclination angle of 20°.

[0039] In summary, this test method for the operation of flow arresters in high-temperature reactor fuel loading and unloading systems verifies the stable operation of flow arresters by conducting operational tests on a test bench. The use of multiple graphite ball elements in the verification test improves the accuracy of the verification structure and ensures that the verified flow arresters can operate continuously and stably. This guides the factory acceptance process for flow arresters and improves their availability.

[0040] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system, characterized in that, This includes an exit ball disturbance test and an entrance ball disturbance test. The exit ball disturbance test includes the following steps: A1: Construct a test bench and install a flow restrictor inside the test bench; A2: Set up the driver and enter the choke operation program from step A1 into the driver; A3: Power on the current blocker and the driver; A4: Supply gas to the outlet pipe of the flow restrictor, the flow restrictor performs the ball feeding action, place multiple graphite ball elements at the inlet of the flow restrictor, and start the flow restrictor to deliver multiple graphite ball elements to the downstream pipe of the flow restrictor. A5: The graphite ball elements roll during the conveying process. When the graphite ball elements roll smoothly to the downstream pipe, they will make a sound. If each graphite ball element makes a sound when it rolls to the downstream pipe, it is determined that multiple graphite ball elements have rolled smoothly into the downstream pipe. If the number of sounds is less than the number of graphite ball elements that enter the flow restrictor, it is determined that not all graphite ball elements have rolled smoothly into the downstream pipe. The inlet sphere disturbance test includes the following steps: B1: Construct a test bench and install a flow restrictor inside the test bench; B2: Set up the driver and enter the choke operation program from step A1 into the driver; B3: Power on the choke and driver; B4: Supply gas to the outlet pipe of the flow restrictor, the flow restrictor performs the ball feeding action, at least three graphite ball elements are placed at the outlet of the flow restrictor, and the flow restrictor is started to deliver the three graphite ball elements to the downstream pipe of the flow restrictor. B5: Transport a graphite ball element to the downstream pipeline for the flow restrictor ball removal operation; B6: Add one graphite ball element upstream of the flow stopper to restore the number of balls stored upstream of the flow stopper to 3; Repeat steps B4 and B5 in sequence to ensure that each graphite ball element can roll smoothly from the upstream pipe to the downstream pipe.

2. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In steps A1 and B1, the outlet pressure of the flow restrictor is set to be greater than the inlet pressure, and the pressure difference between the outlet and inlet of the flow restrictor is set to 200 kPa.

3. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In steps A1 and B1, the angle at which the flow restrictor is set needs to be tilted by 20° so that the inlet end of the flow restrictor faces upward.

4. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In both steps A1 and B1, the test bench needs to be assembled under atmospheric conditions.

5. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In steps A4 and B4, the flow restrictor needs to perform the ball feeding action under a differential pressure environment of 200 kPa.

6. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In step B6, the movement status of the two graphite ball elements stored upstream needs to be visually inspected during the ball retrieval process.

7. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, In step B6, when step B5 is repeated, it is necessary to visually inspect the disturbance to the upstream temporary graphite ball element when the flow restrictor performs the ball-taking operation under differential pressure conditions.

8. The test method for the operation of the flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 7, characterized in that, When the flow restrictor is used to retrieve the ball, the disturbance to the graphite ball element temporarily stored in the upstream pipe of the flow restrictor can be restored to stillness within 3 seconds, which is an acceptable standard.

9. The test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 1, characterized in that, The test bench includes a support block (5), a flow obstructor (1) obliquely arranged on the support block (5), a flow ball tube arranged on the flow obstructor (1), a flow obstructor (1) arranged on the flow ball tube, and an air supply pipe connected to the flow ball tube; the air inlet of the air supply pipe is provided with a Roots blower (4), the air outlet of the air supply pipe is connected to the flow ball tube, a pressure reducing valve (2) is provided at one end of the air supply pipe near the flow ball tube, and a buffer tank (3) is provided between the Roots blower (4) and the pressure reducing valve (2).

10. The test method for the operation of a flow restrictor in a high-temperature reactor fuel loading and unloading system according to claim 9, characterized in that, The support block (5) is a wedge-shaped block with an inclined surface, and the flow block (1) is disposed on the inclined surface of the wedge-shaped block, the inclined surface having an inclination angle of 20°.

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