A test device and method for verifying the sealing performance of an inflatable cofferdam

Abstract

The invention discloses a test device and method for verifying the sealing performance of an inflatable cofferdam, which includes a support stand, a sealing gate, a clamping plate and a pressure regulating mechanism. The support stand includes a plurality of stainless steel coatings, which are divided into a bottom steel coating, a steel coating transition section and a vertical steel coating. The front and rear ends of the steel coating transition section are respectively welded to the vertical steel coating and the bottom steel coating. The beneficial effect is that the test device provides a stand simulating the stainless steel coating of a refueling pool, which meets the on-site working conditions of an inflatable cofferdam of a refueling pool. By operating the pressure regulating mechanism, the sealing pressure ratio of the sealing airbag of the inflatable cofferdam can be adjusted during the sealing test. The test method can determine the critical sealing pressure value of the sealing airbag of the inflatable cofferdam. The test method can simultaneously verify the sealing performance of the sealing airbag of the inflatable cofferdam and the sealing strip between the combined water retaining plate. The test device has a simple structure, is easy to process and has strong practicality.

Description

Technical Field

[0001] The invention belongs to the field of nuclear power plant maintenance, and in particular relates to a test device and method for verifying the sealing performance of an inflatable cofferdam. Background Art

[0002] The sealing boundary of the inflatable cofferdam of the refueling pool of a pressurized water reactor nuclear power plant is composed of a sealing airbag and a sealing strip between the combined water retaining plates, forming an effective isolation on the stainless steel covering of the refueling pool. A mechanical extrusion type double P passive rubber sealing strip is equipped between the combined water retaining plates of the inflatable cofferdam, and a special pressure plate for installing the sealing strip is designed. The sealing strip is embedded in the bottom of the pressure plate and is sealed by fastening and connecting with hinges. A groove is provided at the frame where the inflatable cofferdam contacts the stainless steel covering of the refueling pool, and the sealing airbag is installed and fixed in the groove. The total length of the inflatable cofferdam is less than the minimum span of the stainless steel covering of the refueling pool. The gap is expanded and deformed by the sealing airbag under the action of air pressure, and is effectively compensated after being squeezed with the working surface of the stainless steel covering of the refueling pool, including the wave concave and convex surface of the stainless steel covering, through the weld and the transition fillet, so as to form a reliable seal.

[0003] In order to ensure that the inflatable cofferdam can achieve the function of sealing and isolating the stainless steel covering of the refueling pool, the sealing structure composed of the sealing airbag and the sealing strip between the combined water retaining plate is the key element. Technically, it is necessary to provide a set of test equipment and methods to verify the sealing performance of the inflatable cofferdam, and to simulate the on-site operating conditions of the inflatable cofferdam to verify and optimize the sealing structure and sealing performance. Summary of the invention

[0004] The purpose of the present invention is to provide a test device and method for verifying the sealing performance of an inflatable cofferdam, which can meet the on-site working conditions of the inflatable cofferdam in the refueling pool of a pressurized water reactor nuclear power plant, and conduct a sealing test on the inflatable cofferdam to facilitate verification and optimization of the sealing structure and sealing performance.

[0005] The technical solution of the present invention is as follows: a test device for verifying the sealing performance of an inflatable cofferdam, which includes a support frame, a sealing gate, a positioning plate and a pressure regulating mechanism. The support frame includes a plurality of stainless steel coatings, and the stainless steel coatings are divided into a bottom steel coating, a steel coating transition section and a vertical steel coating. The front and rear ends of the steel coating transition section are respectively welded to the vertical steel coating and the bottom steel coating.

[0006] The support frame is a U-shaped frame structure as a whole, the length of which is the same as the span of the refueling pool, and the entire test device simulates the refueling pool stainless steel covering.

[0007] A sealing gate is arranged on one side of the supporting frame, and both ends are fixedly connected to the stainless steel cladding by bolts.

[0008] The sealing gate is a rectangular plate-shaped structure, and the overall length matches the supporting frame.

[0009] A sealing strip is arranged on the outer periphery of the sealing gate plate, and the sealing strip is pressed by angle steel to compensate for the gap between the sealing gate plate and the supporting frame.

[0010] Two plate-shaped retaining plates are arranged on the two sides of the sealing gate plate. The retaining plates are welded to the sealing gate plate, and a U-shaped retaining groove is arranged in the middle of the retaining plates.

[0011] The pressure regulating mechanism is arranged between the inflatable cofferdam and the sealing gate plate, and is used for regulating the sealing specific pressure of the inflatable cofferdam sealing airbag during the test.

[0012] The pressure regulating mechanism comprises a hand wheel, a lead screw, a pressing piece, a bayonet pressure plate and a base, and the pressure regulating mechanism is supported on a supporting frame through the base.

[0013] The head of the pressure piece is provided with a groove structure adapted to the size of the inflatable cofferdam, which is used to be sleeved on the upper end of the inflatable cofferdam. The handwheel is fixed to the top of the screw by a key and a nut, and is used to drive the screw to rotate. The screw can convert the horizontal rotation of the handwheel into the up and down movement of the pressure piece.

[0014] A test method for verifying the sealing performance of an inflatable cofferdam comprises the following steps:

[0015] (1) Complete the air tightness test: Connect the air inlet pipeline and pressure gauge to the inflatable cofferdam sealing airbag, slowly fill it with compressed air of a certain pressure, maintain the pressure for ten minutes, and then immerse the sealing airbag completely in water to check the air tightness of the sealing airbag;

[0016] (2) Complete the assembly of the pressure regulating mechanism, and assemble the hand wheel, the lead screw, the pressing piece, the limit nut, the lead screw nut, the bayonet pressure plate and the base into a complete pressure regulating mechanism;

[0017] (3) Install the sealing gate, the inflatable cofferdam and the pressure regulating mechanism on the support frame so that the sealing gate, the support frame and the inflatable cofferdam together form a sealed and reliable closed space;

[0018] (4) Complete the critical sealing test and determine the critical sealing pressure value and the normal working pressure value: slowly fill the inflatable cofferdam sealing airbag with compressed air of a certain pressure, and gradually fill the enclosed space with 0.3 to 0.5 meters of water level, and observe the sealing condition of the inflatable cofferdam. If there is no leakage, reduce the initial air pressure by 10% and continue to observe. Repeat this process until the inflatable cofferdam leaks. The air pressure value of the last test is used as the critical sealing pressure value under the corresponding water level, and the normal working pressure value of the corresponding water level is calculated according to a safety margin of 1.2 times;

[0019] (5) Complete the long-term sealing test: The inflatable cofferdam is kept under normal working pressure at a water level of 0.3 to 0.5 meters for 24 hours to check the long-term sealing performance of the inflatable cofferdam;

[0020] (6) Complete the high-pressure strength test: Slowly fill the sealing airbag of the inflatable cofferdam with compressed air at 2 to 4 times the normal working pressure in steps, fill the enclosed space with a water level of 0.3 to 0.5 meters, check the sealing condition of the inflatable cofferdam, maintain the pressure for two hours, and check the structural integrity of the sealing airbag and the inflatable cofferdam body under high pressure conditions.

[0021] The beneficial effects of the present invention are:

[0022] (1) The test device provides a stainless steel-clad bench to simulate the refueling pool, meeting the on-site working conditions of the inflatable cofferdam of the refueling pool.

[0023] (2) By operating the pressure regulating mechanism, the sealing pressure ratio of the sealing airbag of the inflatable cofferdam can be adjusted during the sealing test.

[0024] (3) The test method can determine the critical sealing pressure value of the sealing airbag of the inflatable cofferdam.

[0025] (4) The test method can simultaneously verify the sealing performance of the sealing airbag of the inflatable cofferdam and the sealing strip between the combined water retaining plate.

[0026] (5) The test device has a simple structure, is easy to process, and is highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 The overall schematic diagram of a test device for verifying the sealing performance of an inflatable cofferdam provided by the present invention;

[0028] Figure 2 A left view of a sealing gate plate and a retaining plate of a test device for verifying the sealing performance of an inflatable cofferdam provided by the present invention;

[0029] Figure 3 The present invention provides a schematic diagram of the structure of a pressure regulating mechanism of a test device for verifying the sealing performance of an inflatable cofferdam.

[0030] In the figure, 1 is an inflatable cofferdam, 2 is a supporting frame, 3 is a sealing gate, 4 is a pressure regulating mechanism, 5 is a bottom steel cladding, 6 is a steel cladding transition section, 7 is a vertical steel cladding, 8 is a positioning plate, 9 is a sealing strip, 10 is a handwheel, 11 is a lead screw, 12 is a pressing piece, 13 is a limiting nut, 14 is a lead screw nut, 15 is a bayonet pressure plate, and 16 is a base. DETAILED DESCRIPTION

[0031] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] The present invention adopts a U-shaped frame as a stand, and the two sides are open structures, which are used to simulate the stainless steel covering of the refueling pool. A gate is arranged on one side of the open structure, and a sealing strip is arranged on the outer periphery of the gate, and a plate-like structure with a U-shaped slot is arranged on both sides of the gate. The gate, the stand and the inflatable cofferdam together form a sealed and reliable closed space. A set of adjustment mechanisms is arranged between the gate and the inflatable cofferdam, and the adjustment mechanism is provided with a groove structure, which is sleeved on the upper end of the inflatable cofferdam. The adjustment mechanism is also provided with a convex shaft structure, and the convex shaft structure is connected to the U-shaped slot as a whole.

[0033] When conducting a sealing performance test, the inflatable cofferdam is installed on a test bench. When the inflatable sealing airbag is filled with a certain amount of compressed air and expands and deforms, the adjusting mechanism is operated to generate a sealing pressure ratio between the inflatable sealing airbag and the working surface of the test bench. The enclosed space formed by the gate, the test bench and the inflatable cofferdam can be filled with water to verify the sealing performance of the inflatable cofferdam.

[0034] Specifically, Figure 1 As shown, this embodiment provides a test device for verifying the sealing performance of an inflatable cofferdam, including a support frame 2, a sealing gate plate 3, a positioning plate 8 and a pressure regulating mechanism 4, etc.

[0035] The support frame 2 is a U-shaped frame structure as a whole. Figure 1 As shown, the length is the same as the span of the refueling pool, which is the stainless steel covering of the refueling pool simulated by the entire test device. The support frame 2 body is composed of a plurality of stainless steel coverings, which are divided into a bottom steel covering 5, a steel covering transition section 6 and a vertical steel covering 7. The bottom steel covering 5 is used to simulate the through weld of the stainless steel covering of the refueling pool. The front and rear ends of the steel covering transition section 6 are respectively welded to the vertical steel covering 7 and the bottom steel covering 5 to compensate for the installation gap between the two and simulate the transition radius of the stainless steel covering of the refueling pool. The vertical steel covering 7 is provided with a mounting hole for fixing and connecting the sealing gate 3.

[0036] The sealing gate 3 is arranged on one side of the supporting frame 2, and both ends are fixedly connected to the stainless steel cladding by bolts. Figure 2 As shown, the sealing gate plate 3 is a rectangular plate-shaped structure, and the overall length matches the support frame 2. A sealing strip 9 is arranged on the outer periphery of the sealing gate plate 3, and the sealing strip 9 is pressed by angle steel to compensate for the gap at the joint between the sealing gate plate 3 and the support frame 2.

[0037] like Figure 2 As shown, two plate-shaped retaining plates 8 are provided on the two sides of the sealing gate 3, and the retaining plates 8 are welded to the sealing gate 3. A U-shaped retaining groove is provided in the middle of the retaining plate, which is used to fix the retaining pin pressure plate 15 of the pressure regulating mechanism 4, and supports the pressure regulating mechanism 4 during the test.

[0038] The pressure regulating mechanism 4 is arranged between the inflatable cofferdam 1 and the sealing gate plate 3, and is used to adjust the sealing specific pressure of the sealing airbag of the inflatable cofferdam 1 during the test. Figure 3 As shown, the pressure regulating mechanism 4 includes a hand wheel 10, a lead screw 11, a pressing member 12, a latch pressing plate 15 and a base 16. The pressure regulating mechanism 4 is supported on the supporting frame 2 through the base 16.

[0039] The head of the pressing member 12 is provided with a groove structure adapted to the size of the inflatable cofferdam 1, which is used to be sleeved on the upper end of the inflatable cofferdam 1. The handwheel 10 is fixed to the top of the screw 11 by a key and a nut, and is used to drive the screw 11 to rotate. The screw 11 can convert the horizontal rotation of the handwheel 10 into the up and down movement of the pressing member 12. When in use, when the sealing airbag of the inflatable cofferdam 1 is filled with a certain amount of compressed air to expand and deform, the handwheel 10 is manually shaken to drive the screw 11 to rotate, and then the pressing member 12 is driven to press downward on the upper end of the inflatable cofferdam 1, so that the sealing airbag and the working surface of the support stand 2 form a certain sealing pressure ratio, and it is adjusted according to the test needs. The latch plate 15 is provided with a convex shaft structure adapted to the size of the U-shaped slot of the latch plate 8, and the convex shaft structure is connected to the latch plate 8 as a whole by bolts, thereby supporting the pressure regulating mechanism 4.

[0040] The pressure regulating mechanism 4 further includes a limiting nut 13 and a lead screw nut 14, both of which are in the shape of an annulus. There are two limiting nuts 13, which are respectively arranged at the upper end and the lower end of the lower pressing member 12, and are used to limit and fix the lower pressing member 12; the lead screw nut 14 is connected to the middle and lower part of the lead screw 11 by threads, and has four mounting holes evenly arranged along the circumference of the annulus, which are used to fix the bayonet pressing plate 15.

[0041] The support frame 2, the sealing gate plate 3, the positioning plate 8 and the hand wheel 10, the screw 11, the pressing piece 12, the limiting nut 13, the screw nut 14 and the bayonet pressure plate 15 of the pressure regulating mechanism 4 are all made of stainless steel; the base 16 is made of nylon.

[0042] The test device of this embodiment provides a bench with a stainless steel coating simulating a refueling pool, which meets the on-site working conditions of the inflatable cofferdam 1 of the refueling pool. By operating the pressure regulating mechanism 4, the sealing pressure ratio of the sealing airbag of the inflatable cofferdam 1 can be adjusted during the sealing test. The test method can determine the critical sealing pressure value of the sealing airbag of the inflatable cofferdam 1, and can simultaneously verify the sealing performance of the sealing airbag of the inflatable cofferdam 1 and the sealing strip between the combined water retaining plate. At the same time, the test device has a simple structure, is easy to process, and has strong practicality.

[0043] A test method for verifying the sealing performance of an inflatable cofferdam in this embodiment includes the following steps:

[0044] (1) Complete the air tightness test: Connect the air bag of the inflatable cofferdam 1 to the air inlet pipeline and the pressure gauge, slowly fill it with compressed air of a certain pressure, and maintain the pressure for ten minutes. Then immerse the air bag completely in water and check the air tightness of the air bag.

[0045] (2) Complete the assembly of the pressure regulating mechanism 4. That is, the hand wheel 10, the lead screw 11, the pressing member 12, the limit nut 13, the lead screw nut 14, the bayonet pressing plate 15 and the base 16 are assembled into a complete pressure regulating mechanism 4.

[0046] (3) The sealing gate plate 3, the inflatable cofferdam 1 and the pressure regulating mechanism 4 are installed on the supporting frame 2, so that the sealing gate plate 3, the supporting frame 2 and the inflatable cofferdam 1 together form a sealed and reliable closed space.

[0047] (4) Complete the critical sealing test and determine the critical sealing pressure value and the normal working pressure value: slowly fill the sealing airbag of the inflatable cofferdam 1 with compressed air of a certain pressure, and gradually fill the enclosed space with water levels of 0.3 to 0.5 meters, and observe the sealing condition of the inflatable cofferdam 1. If there is no leakage, reduce the initial air pressure by 10% and continue to observe. And so on, until the inflatable cofferdam 1 leaks. The air pressure value of the last test is the critical sealing pressure value at the corresponding water level, and the normal working pressure value at the corresponding water level is calculated according to a safety margin of 1.2 times.

[0048] (5) Complete the long-term sealing test: maintain the pressure of the inflatable cofferdam 1 at a water level of 0.3 to 0.5 meters and normal working pressure for 24 hours to check the long-term sealing performance of the inflatable cofferdam 1.

[0049] (6) Complete the high-pressure strength test: Slowly fill the sealing airbag of the inflatable cofferdam 1 with compressed air of 2 to 4 times the normal working pressure in steps, fill the closed space with a water level of 0.3 to 0.5 meters, check the sealing condition of the inflatable cofferdam 1, maintain the pressure for two hours, and check the structural integrity of the sealing airbag and the inflatable cofferdam 1 body under high pressure conditions.

[0050] The present invention has been described by the above embodiments, but the above embodiments are only for the purpose of example and description, and are not intended to limit the present invention to the described embodiments. In addition, the present invention is not limited to the above embodiments, and more changes can be made according to the guidance of the present invention, and these changes all fall within the scope of the protection claimed by the present invention.

Claims

1. A test method for verifying the sealing performance of an inflatable cofferdam, wherein the device used comprises a support frame, a sealing gate, a positioning plate and a pressure regulating mechanism, wherein the support frame comprises a plurality of stainless steel claddings, wherein the stainless steel claddings are divided into a bottom steel cladding, a steel cladding transition section and a vertical steel cladding, wherein the front and rear ends of the steel cladding transition section are respectively welded to the vertical steel cladding and the bottom steel cladding; The support frame is a U-shaped frame structure as a whole, the length of which is the same as the span of the refueling pool, and the stainless steel covering of the entire test device simulates the refueling pool; A sealing gate is provided on one side of the support frame, and both ends are fixedly connected to the stainless steel cladding by bolts; The sealing gate is a rectangular plate-shaped structure, and the overall length matches the supporting frame; The outer periphery of the sealing gate is provided with a sealing strip, which is compressed by an angle steel to compensate for the gap between the sealing gate and the supporting frame; Two plate-shaped retaining plates are arranged on the two sides of the sealing gate, the retaining plates are welded to the sealing gate, and a U-shaped retaining groove is arranged in the middle of the retaining plates; The pressure regulating mechanism is arranged between the inflatable cofferdam and the sealing gate plate, and is used to adjust the sealing specific pressure of the inflatable cofferdam sealing airbag during the test; The pressure regulating mechanism comprises a hand wheel, a screw, a pressing piece, a bayonet pressure plate and a base, and the pressure regulating mechanism is supported on a supporting frame through the base; The head of the pressing piece is provided with a groove structure adapted to the size of the inflatable cofferdam, which is used to be sleeved on the upper end of the inflatable cofferdam. The handwheel is fixed to the top of the lead screw through a key and a nut, which is used to drive the lead screw to rotate. The lead screw can convert the horizontal rotation of the handwheel into the up and down movement of the pressing piece. It is characterized in that The following steps are involved: (1) Complete the air tightness test: Connect the air inlet pipeline and pressure gauge to the inflatable cofferdam sealing airbag, slowly fill it with compressed air of a certain pressure, maintain the pressure for ten minutes, and then immerse the sealing airbag in water to check the air tightness of the sealing airbag; (2) Complete the assembly of the pressure regulating mechanism, and assemble the hand wheel, lead screw, lower pressure piece, limit nut, lead screw nut, bayonet pressure plate and base into a complete pressure regulating mechanism; (3) Install the sealing gate, the inflatable cofferdam and the pressure regulating mechanism on the supporting frame so that the sealing gate, the supporting frame and the inflatable cofferdam together form a sealed and reliable closed space; (4) Complete the critical sealing test and determine the critical sealing pressure value and the normal working pressure value: slowly fill the inflatable cofferdam sealing airbag with compressed air of a certain pressure, and gradually fill the enclosed space with a water level of 0.3 to 0.5 meters. Observe the sealing condition of the inflatable cofferdam. If there is no leakage, reduce the initial air pressure by 10% and continue to observe. Repeat this process until the inflatable cofferdam leaks. The air pressure value of the last test is the critical sealing pressure value at the corresponding water level. Calculate the normal working pressure value at the corresponding water level with a safety margin of 1.2 times; (5) Complete the long-term sealing test: the inflatable cofferdam is kept under normal working pressure at a water level of 0.3 to 0.5 meters for 24 hours to check the long-term sealing performance of the inflatable cofferdam; (6) Complete the high-pressure strength test: Slowly fill the sealing airbag of the inflatable cofferdam with compressed air at 2 to 4 times the normal working pressure in steps, fill the enclosed space with a water level of 0.3 to 0.5 meters, check the sealing condition of the inflatable cofferdam, maintain the pressure for two hours, and check the structural integrity of the sealing airbag and the inflatable cofferdam body under high pressure conditions.

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