Nuclear power plant finger casing complete spare parts hydraulic test system

Abstract

The present invention relates to a nuclear power plant finger sleeve complete spare parts water pressure test system, including a water tank, a diaphragm pump, a booster, a control valve, and a pressure detection device; the water tank, the diaphragm pump, the booster, and the control valve are connected in sequence, and the diaphragm pump transports the water in the water tank to the booster; the booster pressurizes the water and transports it to each detection station through a number of control valves; the pressure detection device detects the water pressure transported by the booster. Using a set of industrial water pressure test systems and tooling, a variety of water pressure test methods can be implemented for nuclear power plant finger sleeve complete spare parts, which can be compatible with internal and external pressure testing, local and overall inspections, and batch testing can be realized, and the test process can be automatically controlled.

Description

Technical Field

[0001] The invention relates to the field of nuclear power, and more particularly to a nuclear power plant finger casing complete spare parts water pressure test system. Background Art

[0002] There are 50 neutron flux measurement channels in the nuclear power plant, distributed in 50 fuel assemblies. In the measurement channels of these 50 fuel assemblies, finger sleeves are inserted from the bottom of the core, and the detectors move inside the finger sleeves, so as to measure the neutron flux point by point over the entire height of the core.

[0003] The finger sleeve is also called "active sleeve", with a length ranging from 13.3 to 16.2m, an outer diameter of 8.6mm and a maximum thickness of 1.7mm. A bullet-shaped end plug is welded to one end of the finger sleeve inserted into the core, and a flange-shaped limit block is welded downstream of the sealing section. The outer wall of the finger sleeve is in direct contact with the primary water circuit and also withstands the same water pressure as the reactor pressure. Generally, the complete spare parts of the finger sleeve mainly include four parts: the bullet head (bullet-shaped end plug), finger sleeve, thrust ring and extension section. Assembly and welding are carried out according to technical requirements, and penetration inspection is carried out during the process. After assembly is completed, a water pressure test is carried out to verify its strength, and a helium leak test and eddy current inspection are carried out to verify its sealing, in order to confirm that the finger sleeve spare parts can meet the safe operation of the nuclear power plant after being replaced into the system.

[0004] According to the requirements of standard RCCM3304 and technical specifications, the technical requirements for the hydraulic test of complete casing spare parts are: test pressure is 258bar+10 / 0, pressure holding time is 5min, test medium is deionized water, and the pressure rise and fall rate does not exceed 10bar / min. Acceptance standard: pressure drop within 5min ≤5bar.

[0005] The existing problem is that in the past, the complete spare parts of the finger sleeve were supplied by foreign countries, and the foreign suppliers blocked the technical details of the relevant manufacturing and inspection processes. There were no relevant suppliers in China to implement the assembly and inspection of the finger sleeve spare parts. In this stage, in order to realize the localization and independence of the finger sleeve spare parts, it is necessary to develop corresponding supporting inspection processes, investigate the completion report of imported finger sleeve spare parts, and find the shortcomings of the current technology:

[0006] The single-finger sleeve pressure test tooling design cannot be used for batch water pressure testing;

[0007] The pressure gauge has a reading of about 5 bar, so it is not suitable to control the pressure increase and decrease rate during the test;

[0008] The hydrostatic test process only applies external pressure to the bullet head weld (S3 weld) and fails to cover the entire spare part. Summary of the invention

[0009] The technical problem to be solved by the present invention is to provide a nuclear power plant finger casing complete spare parts water pressure test system in view of the above-mentioned defects of the prior art.

[0010] The technical solution adopted by the present invention to solve the technical problem is: construct a nuclear power plant finger casing complete spare parts water pressure test system, including a water tank, a diaphragm pump, a booster device, a control valve, and a pressure detection device;

[0011] The water tank, the diaphragm pump, the booster device, and the control valve are connected in sequence, and the diaphragm pump transports the water in the water tank to the booster device;

[0012] The booster device boosts the water pressure and then delivers it to each inspection station through a plurality of control valves;

[0013] The pressure detection device detects the water pressure delivered by the booster device.

[0014] Preferably, the boosting device comprises a servo boosting cylinder.

[0015] Preferably, a high-pressure container is provided between the boosting device and the control valve, and a normally-open air-controlled valve is provided between the high-pressure container and the control valve.

[0016] Preferably, the control valve is a pneumatic stop valve, the outlet of the control valve is a high-pressure outlet, and the high-pressure outlet is connected to the detection station.

[0017] Preferably, the system further comprises an overflow valve arranged between the diaphragm pump and the boosting device, and a normally closed air-controlled valve is further arranged between the overflow valve and the boosting device.

[0018] Preferably, the water tank is provided with a splash-proof breathing valve, a liquid level switch, and a liquid level meter.

[0019] Preferably, the pressure detection device comprises a first pressure detection component for detecting the water pressure delivered by the boosting device to the control valve.

[0020] Preferably, the first pressure detection assembly comprises a first pressure sensor and a first pressure gauge which are connected to the outlet of the boosting device.

[0021] Preferably, the pressure detection device further comprises a second pressure detection component for detecting the water pressure in the detection station.

[0022] Preferably, the system also includes a control unit, which includes a power supply, a controller, a servo drive, a servo motor, a pneumatic valve, and a pneumatic pump. The controller is electrically connected to the power supply, the servo drive, the pneumatic valve, and the pneumatic pump are electrically connected to the controller, respectively, and the servo motor is electrically connected to the servo drive.

[0023] The nuclear power plant finger casing complete spare parts hydraulic pressure test system implementing the present invention has the following beneficial effects: using a set of industrial hydraulic pressure test system and tooling, a variety of hydraulic pressure test methods can be realized for nuclear power plant finger casing complete spare parts, which can be compatible with internal and external pressure testing, local and overall inspection, and batch testing can be realized, and the test process can be automatically controlled. 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 principle of a nuclear power plant finger casing complete spare parts hydraulic test system in an embodiment of the present invention;

[0026] Figure 2 It is a schematic diagram of the structure of the external pressure tooling;

[0027] Figure 3 It is a schematic diagram of the structure of the internal pressing tooling. DETAILED DESCRIPTION

[0028] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific embodiments of the present invention are now described in detail with reference to the accompanying drawings.

[0029] like Figure 1 As shown, a nuclear power plant finger casing complete spare parts hydraulic pressure test system in a preferred embodiment of the present invention includes a water tank 1, a diaphragm pump 2, a booster device 3, a control valve 4, and a pressure detection device.

[0030] The water tank 1, the diaphragm pump 2, the booster device 3, and the control valve 4 are connected in sequence. The diaphragm pump 2 conveys the water in the water tank 1 to the booster device 3. The booster device 3 pressurizes the water and conveys it to the finger sleeves 7 to be tested on each detection station 6 through a plurality of control valves 4, so as to pressurize multiple sets of finger sleeves 7 at the same time. The finger sleeves 7 to be tested are pre-installed on the detection station 6. The water from the control valve 4 enters the finger sleeves 7 to be tested and then undergoes a pressure-maintaining water pressure test. The control valve 4 can independently control the water source of the corresponding water pressure test of the finger sleeves 7 to be tested, so as to facilitate the independent replacement of the finger sleeves 7 to be tested on each detection station 6.

[0031] The pressure detection device detects the water pressure delivered by the booster device 3 and monitors the water pressure in the circuit in real time, so as to provide feedback to the booster device 3 to control the water pressure.

[0032] By using a set of industrial water pressure test system and tooling, a variety of water pressure test methods can be realized for the complete spare parts of nuclear power plant finger casing 7, which can be compatible with internal and external pressure testing, local and overall inspection, batch testing and automatic control of the test process.

[0033] Furthermore, the boosting device 3 includes a servo boosting cylinder, and the diaphragm pump 2 is a pre-filling pump.

[0034] A high-pressure container 31 is further provided between the boosting device 3 and the control valve 4 , and a normally-open air-controlled valve 32 is further provided between the high-pressure container 31 and the control valve 4 .

[0035] The control valve 4 is a gas-controlled stop valve, and the outlet of the control valve 4 is a high-pressure outlet 41 , which is connected to the detection station 6 .

[0036] The system pre-charges the workpiece through the pre-charging pump, fills the pipeline with the medium, and then exhausts the workpiece and pipeline through the external vacuum device, pressurizes and releases the pressure through the servo booster cylinder, and maintains the pressure and unloads the load through the air-controlled stop valve.

[0037] The system further comprises an overflow valve 21 arranged between the diaphragm pump 2 and the boosting device 3 , and a normally closed air-controlled valve 22 is further arranged between the overflow valve 21 and the boosting device 3 .

[0038] The water tank 1 is provided with a splash-proof breathing valve 11, a liquid level switch 12, and a liquid level meter 13 for performing relevant detection and liquid level control.

[0039] Furthermore, the pressure detection device includes a first pressure detection component 51 for detecting the water pressure delivered by the boosting device 3 to the control valve 4 .

[0040] The first pressure detection assembly 51 includes a first pressure sensor and a first pressure gauge which are connected to the outlet of the boosting device 3 .

[0041] The pressure detection device also includes a second pressure detection component 52 for detecting the water pressure in the detection station 6 to test the pressure of the detection station 6 .

[0042] Furthermore, the 30L water tank 1 is used to store the boosting medium; the pneumatic diaphragm pump 2 is used for pre-charging the workpiece and the pipeline; the servo booster cylinder is used for boosting and pressure control; the air control valve and the control valve are used for cut-off, pressure relief and diversion of each workstation; the 2.5L high-pressure container 31 pressure tank is used for pressure buffering and volume control of the boosting rate; the high-pressure pressure gauge is used to intuitively display the current working pressure and determine whether the system has pressure in power-off and fault modes; the local touch screen is used for local equipment operation and can display the pressure-time curve.

[0043] like Figure 2As shown, the tooling of the "bullet head" external pressure testing station 6 is mainly composed of a sealing seat 61, a sealing member 62, a clamping gasket 63, a compression nut 64, etc. The sealing member 62 and the clamping gasket 63 are arranged in order, and the compression nut 64 is not locked first. An erasable position mark is added to the finger sleeve 7, and the bullet head part of the finger sleeve 7 is inserted into the sealing seat 61. The insertion depth is in accordance with the marked position. The compression nut 64 is locked with a crescent wrench according to the specified torque. The clamping gasket 63 is tightened under the pressure of the compression nut 64, thereby holding the finger sleeve 7 tightly. Since the clamping gasket 63 is made of non-metallic material, it will not cause damage to the outer wall of the finger sleeve 7. The pressure inlet 65 is connected to the pressure source for pressure testing. The leak detection port 66 can be used to determine whether the seal 62 is invalid. After the pressure test is completed, the compression nut 64 is loosened and the finger sleeve 7 is taken out. Replace the O-ring and retaining ring according to the test needs.

[0044] like Figure 3 As shown, the tooling of the internal pressure testing station 6 of the finger sleeve 7 is composed of a pressure port connector 67, a seal 62 and a compression nut 64. The pressure port connector 67 is manually pressed into the extension section of the finger sleeve 7. Note that the seal 62 cannot be cut. If necessary, grease can be added. Then the compression nut 64 is locked, and the pressure inlet 65 is connected to the pressure source for testing.

[0045] Preferably, the system also includes a control unit, which includes a power supply, a controller, a servo drive, a servo motor, a pneumatic valve, and a pneumatic pump. The controller is electrically connected to the power supply, the power supply is a DC24V power supply, the controller is a PLC controller, the servo drive, the pneumatic valve, and the pneumatic pump are respectively electrically connected to the controller, and the servo motor is electrically connected to the servo drive.

[0046] Equipment operation process:

[0047] 1) Preset the workstations that need to be pressed on the touch screen or the user's display (a total of 5 workstations), preset working pressure, pressure increase and decrease rate, pressure holding time and other parameters.

[0048] 2) First, use the pre-filled diaphragm pump 2 to fill the system with the medium, and then connect the vacuum pump 42 to the vacuum port to evacuate and exhaust the workpiece end;

[0049] 3) After exhausting, start the pre-filling diaphragm pump 2 to pre-fill the workpiece so that the workpiece is filled with the medium. The maximum pre-filling pressure is 6 bar;

[0050] 4) The electric servo booster cylinder will automatically pressurize the tooling at the set pressure increase rate and stop when the target pressure reaches 258 bar.g. At this time, the pressure maintenance command is executed.

[0051] 5) When maintaining pressure, the stop valve of each workstation is closed, and the pressure drop is read through the pressure sensor that comes with each set of tooling.

[0052] 6) After the preset pressure maintaining time, the system pressure relief valve opens and automatically releases pressure at the preset pressure reduction rate.

[0053] Note: When increasing or decreasing pressure, the 5 stations can only be performed step by step. They can only be performed simultaneously when their test pressures are the same and the increase or decrease rates are the same.

[0054] The specific implementation method is as follows:

[0055] 1. A two-stage pressure test process was designed. First, the test system was pre-pressurized to 4 bar using a pneumatic diaphragm pump 2, and then the servo booster cylinder was used to boost the pressure to a test pressure of 258 bar.

[0056] 2. Considering that the volume of the test object is very small and the pressure increase and decrease rate control is difficult, a 1L high-pressure container 31 buffer tank is added to the pressure system to cooperate with the servo hydraulic cylinder for pressure regulation;

[0057] 3. According to the thread structure (M27*1.5) of the extension section of the complete spare finger sleeve 7, a high-pressure hose with matching threads and water inlet and exhaust and pressure monitoring tooling is customized to cooperate with the extension section of the finger sleeve 7 to achieve overall pressure testing. It can be put on the outside of the finger sleeve 7 to achieve external pressure testing, and connected to the tail of the extension section to achieve internal pressure testing.

[0058] 4. Using the RIC sealing component structure on the power station system, the enveloping bullet weld can be locally pressed;

[0059] 5. Design 5-way water pressure test booster branches and pressure test tooling, and use PLC control system to realize automated batch test operations.

[0060] The advantages and beneficial effects of using the technology of this application are as follows:

[0061] 1) Improve safety level: The overall pressure test of complete spare parts can effectively verify the safety and reliability of key components;

[0062] 2) Save overhaul time: Through the research of independent detection technology, we can take the initiative in replacing the finger sleeve 7 and save the overhaul path;

[0063] 3) Save procurement costs: localize spare parts and avoid high-priced procurement, saving more than 500,000 yuan for a single finger sleeve

[0064] Innovations of this application:

[0065] Establish domestic finger sleeve 7 complete spare parts hydraulic pressure test method;

[0066] Achieve local and overall water pressure test of complete spare parts of finger sleeve 7;

[0067] Achieve external and internal water pressure test of complete spare parts of finger sleeve 7;

[0068] The complete spare parts of the finger sleeve 7 can be automatically pressed in batches, and the pressure increase and decrease rate can be controlled.

[0069] The application of this application will produce the following contributions:

[0070] The localization of the water pressure test for the inspection of the complete spare parts of the finger sleeve 7 is realized, and the finger sleeve 7 can be replaced at any time according to the maintenance needs, thereby reducing the foreign procurement cost and improving the economic benefits of power generation.

[0071] It can be understood that the above-mentioned technical features can be used in any combination without limitation.

[0072] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, 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 nuclear power plant finger casing complete spare parts hydraulic pressure test system, characterized in that: It comprises a water tank (1), a diaphragm pump (2), a pressure boosting device (3), a control valve (4), and a pressure detection device; The water tank (1), the diaphragm pump (2), the pressure-boosting device (3), and the control valve (4) are connected in sequence, and the diaphragm pump (2) transports the water in the water tank (1) to the pressure-boosting device (3); The pressure-boosting device (3) pressurizes the water and then delivers the water to each detection station (6) through a plurality of control valves (4); The pressure detection device detects the water pressure delivered by the booster device (3); The boosting device (3) comprises a servo boosting cylinder; The diaphragm pump (2) is a pre-filling pump; The detection station (6) comprises a sealing seat (61), a clamping gasket (63), a compression nut (64), a pressure inlet (65), and a pressure port joint (67); When conducting an external pressure test, an erasable position mark is added to the finger sleeve (7) to be tested, and the bullet head portion of the finger sleeve (7) is inserted into the sealing seat (61) to a depth corresponding to the marked position. The clamping nut (64) is tightened according to a specified torque, and the clamping gasket (63) is tightened under the pressure of the clamping nut (64), thereby holding the finger sleeve (7) tightly. The pressure inlet (65) is connected to a pressure source for testing; When performing an internal pressure test, the pressure port connector (67) is manually pressed into the extension section of the finger sleeve (7) to be tested, and the compression nut (64) is tightened, and the pressure inlet (65) is connected to a pressure source for testing.

2. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1 is characterized in that: A high-pressure container (31) is also provided between the pressure-boosting device (3) and the control valve (4), and a normally open air-controlled valve (32) is also provided between the high-pressure container (31) and the control valve (4).

3. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1 is characterized in that: The control valve (4) is a gas-controlled stop valve, the outlet of the control valve (4) is a high-pressure outlet (41), and the high-pressure outlet (41) is connected to the detection station (6).

4. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1 is characterized in that: The system further comprises an overflow valve (21) arranged between the diaphragm pump (2) and the pressure boosting device (3), and a normally closed air control valve (22) is also arranged between the overflow valve (21) and the pressure boosting device (3).

5. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1, characterized in that: The water tank (1) is provided with an anti-splash breathing valve (11), a liquid level switch (12), and a liquid level meter (13).

6. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1, characterized in that: The pressure detection device comprises a first pressure detection component (51) for detecting the water pressure delivered by the pressure boosting device (3) to the control valve (4).

7. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 6, characterized in that: The first pressure detection assembly (51) comprises a first pressure sensor and a first pressure gauge which are connected to the outlet of the boosting device (3).

8. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1, characterized in that: The pressure detection device also includes a second pressure detection component (52) for detecting the water pressure in the detection station (6).

9. The nuclear power plant finger casing complete spare parts hydraulic pressure test system according to claim 1, characterized in that: The system also includes a control unit, which includes a power supply, a controller, a servo drive, a servo motor, an air-controlled valve, and a pneumatic pump. The controller is electrically connected to the power supply, the servo drive, the air-controlled valve, and the pneumatic pump are electrically connected to the controller respectively, and the servo motor is electrically connected to the servo drive.

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