Performance test device and method for submersible pump used for bucket foundation penetration construction

Abstract

Disclosed in the present invention are a performance test device and method for a submersible pump used for bucket foundation penetration construction. The test device comprises a sealed box, a submersible pump, a test pit, a pressurized airbag, an air storage tank, ballast blocks and a monitoring platform. An opening at the bottom of a side plate of the sealed box is connected to an opening valve; an internal pressure sensor is mounted on an opening on a top plate of the sealed box, and an external pressure sensor is mounted on the top surface of the top plate; the submersible pump is mounted in a water pump frame placed on the top plate of the sealed box, so that a water inlet of the submersible pump is connected to a water outlet pipe of the sealed box; a flow sensor is mounted at a water outlet of the submersible pump; a cover plate covers the top of the test pit; the pressurized airbag is mounted on the bottom surface of the cover plate; an air outlet of the air storage tank is connected to an inflation port of the pressurized airbag; the ballast blocks are stacked on the cover plate; and the monitoring platform is arranged on the ground near the test pit. The sealed box is placed on the bottom plate of the test pit, and the water level in the test pit is close to the top. The present invention can provide quantitative support for the selection of submersible pumps for bucket foundation penetration construction.

Description

A performance testing device and method for a submersible pump used in the sinking and penetration construction of a bucket foundation. Technical Field

[0001] This invention relates to a performance testing device and method for a submersible pump used in the sinking and penetration construction of a bucket foundation. Background Technology

[0002] Bucket foundations are a novel structure with an open bottom and a closed top. They utilize water pumping to create a pressure difference between the inside and outside of the bucket, overcoming resistance to sink. They are particularly suitable for soft clay seabeds and offer advantages such as no need for large equipment during sinking, short operation time, and noiseless construction. They are used in both marine and water transport engineering. A typical bucket foundation 10 includes four side walls 11 and a top cover 12. During the installation of the bucket foundation 10, it first sinks to a certain depth under its own weight, overcoming resistance. Then, the submersible pump 2 installed on the top cover 12 is activated. Water is pumped from the closed space inside the bucket filled with water into the open water area, making the water pressure inside the bucket lower than the external environmental water pressure, thus creating a pressure difference (referred to as "pressure differential"). Under the action of this pressure difference, the sinking resistance is overcome, and the foundation is installed (see Figures 1a and 1b). The submersible pump is the core equipment in the bucket foundation installation process, but its selection still faces difficulties.

[0003] Submersible pumps are commonly used to lift water to a certain height in open water bodies, such as water wells and oil wells. Submersible pump specifications typically provide a performance curve, showing the relationship between flow rate and head at a given power or speed. Head refers to the height the pump can lift water; it is determined by the difference between the test results of the two pressure sensors installed at the pump's inlet and outlet during operation. Flow rate is obtained using a flow sensor. A typical submersible pump testing setup includes a test pit 3, a submersible pump 2 installed within a pump frame 21, an inlet pipe 22 connected to the inlet of the submersible pump 2, a drain pipe 23 connected to the outlet of the submersible pump 2, a pressure sensor 24 installed on the inlet pipe 22, and a flow sensor 25 installed on the drain pipe 23 (see Figure 2). It should be noted that the performance test results of a typical submersible pump are not significantly affected by water depth; the test water depth only needs to cover the submersible pump and meet its operating conditions.

[0004] In the conventional selection process of submersible pumps, you can first determine the required head and flow rate based on the application scenario, and then refer to the performance curve of the submersible pump provided by the submersible pump manufacturer to find the point on the curve that corresponds to the required value to ensure that the submersible pump can operate effectively. Finally, you also need to comprehensively consider the performance, power consumption and other specific application scenario factors of the submersible pump under working conditions to complete the selection of the submersible pump.

[0005] For submersible pumps used in bucket foundation settling, the most important parameter is the relationship between flow rate and pressure difference across the bucket at a given power (speed), rather than the conventional relationship between head and flow rate. Furthermore, since the pressure difference across the bucket is related to both flow rate and water depth, the influence of water depth must be considered. Currently, no submersible pump manufacturers provide pump performance curves suitable for selecting submersible pumps for bucket foundation settling, nor are there dedicated testing devices for measuring the relationship between the flow rate of a submersible pump and the pressure difference across the bucket. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a performance testing device and method for submersible pumps used in the sinking construction of bucket foundations, which can provide quantitative support for the selection of submersible pumps used in the sinking construction of bucket foundations.

[0007] One technical solution to achieve the objective of this invention is: a performance testing device for a submersible pump used in the sinking construction of a barrel foundation, comprising a sealed box, a submersible pump, a test pit, a pressurization airbag, an air storage tank, a ballast block, hoisting equipment, and a monitoring platform; wherein,

[0008] The sealing box has a water inlet hole at the bottom of its side plate, and an opening valve is connected to the water inlet hole via a water inlet pipe. An internal pressure sensor is installed in the top plate of the sealing box, and an external pressure sensor is installed on the top surface of the top plate. A water outlet hole is provided on the top plate of the sealing box, and a water outlet pipe is welded to the water outlet hole.

[0009] The submersible pump is installed inside the pump frame, which is placed on the top plate of the sealed box, so that the inlet of the submersible pump is connected to the outlet pipe of the sealed box; a flow sensor is installed at the outlet of the submersible pump.

[0010] The test pit is located below ground level. The planar dimensions of the test pit are larger than those of the sealed box, and the depth of the test pit is greater than the sum of the height of the water pump frame and the height of the sealed box. The top of the test pit is covered with a cover plate. The planar dimensions of the cover plate are larger than those of the test pit, and a rubber water-stop pad is provided on the bottom edge of the cover plate to contact the ground.

[0011] The pressurized airbag is laid flat on the bottom surface of the cover plate of the test pit via a bracket;

[0012] The outlet of the air tank is connected to the inflation port of the pressurized air bag through an inflation pipe that passes through an opening in the cover plate, and the inlet of the air tank is connected to an air compressor.

[0013] The ballast blocks are placed on the cover plate of the test pit;

[0014] The hoisting equipment is positioned on the ground above the top surface of the test pit;

[0015] The monitoring platform is located on the ground near the test pit. The monitoring platform is connected to the submersible pump, the opening valve, the internal pressure sensor, the external pressure sensor, the flow sensor, and the air compressor via signal lines.

[0016] The sealed box is placed on the bottom plate of the test pit, and the water level in the test pit is close to the top, leaving room for drainage of the pressurized airbag, so that the test pit is almost full of water after the cover is installed.

[0017] The aforementioned performance testing device for submersible pumps used in the sinking construction of bucket foundations, wherein the sealed box has a volume of not less than 1m³. 3 The sealing box is a cylindrical container; a lifting lug is provided on the top plate of the sealing box; a circumferential reinforcing rib and a radial reinforcing rib are provided on the bottom surface of the top plate and the top surface of the bottom plate of the sealing box, and a transverse reinforcing rib and a vertical reinforcing rib are provided on the inner surface of the side plate of the sealing box.

[0018] The aforementioned performance testing device for a submersible pump used in the sinking construction of a barrel foundation includes a pressurized airbag consisting of multiple airbag strips whose lengths are adapted to the lengths of the cover plate of the test pit and connected in series. All the airbag strips are inflated through an inflation port located in the middle of the airbag strip.

[0019] Another technical solution to achieve the purpose of the present invention is: a performance testing method for a submersible pump used in the sinking construction of a bucket foundation, which adopts the testing device for the performance of a submersible pump used in the sinking construction of a bucket foundation of the present invention. The testing method includes the following steps: test preparation step S1 and test step S2.

[0020] The test preparation process S1 includes the following steps:

[0021] S11, install the opening valve, the pressure sensor inside the box and the pressure sensor outside the box on the sealed box, and install the flow sensor at the outlet of the submersible pump. Then, connect the submersible pump, the opening valve, the pressure sensor inside the box, the pressure sensor outside the box, the flow sensor and the air compressor to the monitoring platform and debug the connection lines. Then, install the submersible pump in the water pump frame, and then place the water pump frame as a whole on the top plate of the sealed box.

[0022] S12, under the condition that there is no water in the test pit, the sealing box and the submersible pump are hoisted together onto the bottom plate of the test pit;

[0023] S13, Initial water filling: Before filling, fully open the valve to allow the gas in the sealed box to be completely discharged and the sealed box to be filled with water. The water level should be enough to submerge the submersible pump. Keep the valve fully open, start the submersible pump to pump water, and test whether the submersible pump, the pressure sensor inside the box, the pressure sensor outside the box, and the flow sensor are working properly.

[0024] S14, Secondary water storage: After ensuring the submersible pump, internal pressure sensor, external pressure sensor and flow sensor are working properly, continue to store water in the test pit until the water level reaches near the cover plate.

[0025] S15, Install a pressurized airbag on the bottom surface of the cover plate of the test pit, and then cover the top of the test pit with the cover plate so that the rubber water-stop pad installed on the bottom edge of the cover plate is in full contact with the ground to form an effective water stop. After the cover plate is installed, the test pit is nearly filled with water. Then, the inflation port of the pressurized airbag is connected to the air tank and the air compressor in sequence through the inflation pipe.

[0026] S16, place ballast blocks on the top surface of the cover plate of the test pit. The weight of the ballast blocks is greater than the pressure generated by the maximum test water depth within the area of ​​the cover plate. At this point, all test preparations are complete.

[0027] The experimental procedure S2 includes the following steps:

[0028] S21, the pressurization airbag is inflated by the air compressor-air tank and pressurized to the specified test pressure Pt, so that the pressure of the pressurization airbag is always kept at Pt, that is, the water depth environment simulation of Pt / 10 is completed.

[0029] S22, simulating the initial working conditions of the bucket foundation's pumping and settling, starts the submersible pump at its rated power and fully opens the valve. At this point, the submersible pump's pumping flow rate is at its maximum, reaching its rated pumping capacity. During this stage, the settling resistance of the bucket foundation is close to its own weight, requiring only a small pressure difference between the inside and outside of the bucket to achieve settling. The pressure difference between the inside and outside of the bucket approaches 0. The valve remains fully open. After the pumping flow rate and the pressure difference between the inside and outside of the bucket stabilize, a set of pumping flow rate q is recorded. 100％ Pressure difference ΔP between inside and outside the box 100％ =P 内100％ -P 外100％ ;P 内100％ The value monitored by the pressure sensor inside the chamber when the valve is 100% open; P 外100％ This is the value monitored by the external pressure sensor when the valve is 100% open;

[0030] S23, simulating the gradual increase in penetration depth of a bucket foundation, the penetration resistance increases accordingly, requiring a certain pressure difference between the inside and outside of the bucket to achieve penetration. With the submersible pump operating at its rated power, the opening of the valve is adjusted to 80%, correspondingly reducing the pump's flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pump's flow rate and the pressure difference monitoring results stabilize, a set of pump's flow rate q is recorded. 80％ Pressure difference ΔP between inside and outside the box 80％ =P 内80％ -P 外80％ ;P内 80％ The value monitored by the pressure sensor inside the chamber when the valve is at 80% opening; P 外80％ This is the value monitored by the external pressure sensor when the valve is at 80% opening.

[0031] S24, simulating the gradual increase in penetration depth of the bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. While maintaining the submersible pump at its rated power, the opening of the valve is adjusted to 60%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 60％ Pressure difference ΔP between inside and outside the barrel 60％ =P 内 60％ -P 外60％ ;P 内60％ The value monitored by the pressure sensor inside the chamber when the valve is at 60% opening; P 外60％ This is the value monitored by the external pressure sensor when the valve is at 60% opening.

[0032] S25, simulating the gradual increase in penetration depth of a bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. With the submersible pump operating at its rated power, the opening of the valve is adjusted to 40%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 40％ Pressure difference ΔP between inside and outside the box 40％ =P 内 40％ -P 外40％ ;P 内40％ The value monitored by the pressure sensor inside the chamber when the valve is at 40% opening; P 外40％ This is the value monitored by the external pressure sensor when the valve is at 40% opening.

[0033] S26. Simulating a bucket foundation, as the penetration depth gradually increases, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. Maintaining the submersible pump at its rated power, the opening of the valve is adjusted to 20%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 20％ Pressure difference ΔP between inside and outside the barrel 20％ =P 内 20％ -P外20％ ;P 内20％ The value monitored by the pressure sensor inside the chamber when the valve is at 20% opening; P 外20％ This is the value monitored by the external pressure sensor when the valve is at 20% opening.

[0034] S27, simulating the difficult settling condition of a bucket foundation under pumping conditions, with the submersible pump operating at its rated power, the opening of the valve is set to 0%, meaning the valve is completely closed. At this stage, the sum of the bucket foundation's self-weight and the pressure difference between the inside and outside of the bucket is still insufficient to overcome the settling resistance. The submersible pump's flow rate approaches 0, and the absolute value of the pressure difference between the inside and outside of the bucket approaches its maximum value, Pt + Ps. Ps is the difference between the absolute pressure inside the bucket and atmospheric pressure caused by the submersible pump pumping water; that is, Ps is the suction force corresponding to the pump's suction head. After the submersible pump's flow rate and the pressure difference between the inside and outside of the bucket stabilize, a set of data is recorded for the submersible pump's flow rate q0 and the pressure difference ΔP0 = P. 内0 -P 外0 ;P 内0 The value monitored by the pressure sensor inside the chamber when the valve is at 0 opening; P 外0 This is the value monitored by the external pressure sensor when the valve is at 0 opening.

[0035] S28, plot the relationship between the pumping flow rate q and the pressure difference ΔP inside and outside the tank of multiple submersible pumps with the same water depth and valve opening degree under different opening degrees as a performance curve of the submersible pump under a given water depth environment.

[0036] S29, adjust the inflation pressure Pt of the booster airbag, i.e. adjust the water depth environment, repeat steps S22 to S28 to obtain the performance curve of the submersible pump under a series of water depth environments.

[0037] The performance testing device and method for submersible pumps used in the sinking construction of bucket foundations of the present invention have the following characteristics:

[0038] 1. Existing submersible pump selection for bucket foundation sinking construction lacks quantitative support for submersible pump performance indicators. The testing device and testing method of this invention provide quantitative support for the selection of submersible pumps for bucket foundation sinking construction.

[0039] 2. Conventional submersible pump performance testing devices cannot simulate pumping water from a confined space. This invention simulates pumping water from a confined space by setting up a sealed box, which is consistent with the actual working conditions of the bucket foundation sinking.

[0040] 3. Conventional submersible pump performance testing devices only test the inlet and outlet pressures of the submersible pump. The testing method of this invention tests the internal and external pressures of the sealed box connected to the submersible pump, which is consistent with the actual working conditions of the bucket foundation sinking.

[0041] 4. Conventional submersible pump performance testing devices do not have a water depth simulation system. The testing method of this invention uses a pressurized airbag to simulate different water depth environments, which can simulate the effects of different water depths without the need for a deep pit. Attached Figure Description

[0042] Figure 1a is a state diagram of the typical settling of a barrel foundation;

[0043] Figure 1b is another state diagram of the settlement of a conventional barrel foundation;

[0044] Figure 2 is a schematic diagram of the structure of a performance testing device for submersible pumps in the prior art;

[0045] Figure 3 is a structural schematic diagram of the performance testing device for the submersible pump used in the sinking construction of the bucket foundation of the present invention.

[0046] Figure 4 is a bottom view of the cover plate of the test pit in the performance testing device of the present invention;

[0047] Figure 4a is a side view of Figure 4;

[0048] Figure 5a is a state diagram during step S12 of the test method of the present invention;

[0049] Figure 5b is a state diagram during step S13 of the test method of the present invention;

[0050] Figure 5c is a state diagram during step S14 of the test method of the present invention;

[0051] Figure 5d is a state diagram during step S15 of the test method of the present invention.

[0052] Figure 5e is a state diagram during step S16 of the test method of the present invention;

[0053] Figure 5f is a state diagram during step S21 of the test method of the present invention;

[0054] Figure 6a is a performance curve of the submersible pump obtained when performing step S28 of the test method of the present invention.

[0055] Figure 6b is a performance curve of the submersible pump obtained during step S29 of the test method of the present invention. Detailed Implementation

[0056] The invention will now be further described with reference to the accompanying drawings.

[0057] Please refer to Figures 3 to 4a. The performance testing device for the submersible pump used in the sinking construction of the barrel foundation of the present invention includes a test pit 3, a sealed box 4, a submersible pump 2, a pressurizing airbag 5, an air storage tank 6, a ballast block 7, a hoisting device 8, and a monitoring platform 9.

[0058] Sealed box 4 has a volume of not less than 1m³ 3 The sealing box 4 is a cylindrical container; a lifting lug 40 is provided on the top plate of the sealing box 4; circumferential reinforcing ribs and radial reinforcing ribs are respectively provided on the bottom surface of the top plate and the top surface of the bottom plate of the sealing box 4; reinforcing ribs 46 are provided on the inner surface of the side plate of the sealing box 4, including transverse reinforcing ribs and vertical reinforcing ribs; a sealing box water inlet hole is opened at the bottom of the side plate of the sealing box 4, and a sealing box water inlet pipe 41 is welded to the sealing box water inlet hole, the other end of the sealing box water inlet pipe 41 is connected to an opening valve 43 through a flange; an internal pressure sensor 44 is installed in the top plate of the sealing box 4, and an external pressure sensor 45 is installed on the top surface of the top plate of the sealing box 4; a sealing box water outlet hole is opened in the top plate of the sealing box 4, and a sealing box water outlet pipe 42 is welded into the sealing box water outlet hole. The measuring range of the internal pressure sensor 44 and the external pressure sensor 45 is -0.1 to 2 MPa, and the measuring accuracy is 0.1%.

[0059] The submersible pump 2 is installed inside the pump frame 21, which is placed on the top plate of the sealed box 4, so that the water inlet of the submersible pump 2 is connected to the water outlet pipe 42 of the sealed box through the water inlet pipe 22; the water outlet of the submersible pump 2 is equipped with a flow sensor 25 through the drain pipe 23.

[0060] The test pit 3 is located below ground level. The test pit 3 has a rectangular plane, and its plane dimensions are larger than those of the sealing box 4. The depth of the test pit 3 is greater than the sum of the height of the water pump frame 21 and the height of the sealing box 4. The top of the test pit 3 is covered by a cover plate 30, the plane dimensions of which are larger than those of the test pit 3. A rubber water-stop pad 31 is provided on the bottom edge of the cover plate 30, which is in contact with the ground. A lifting lug 32 is provided on the top surface of the cover plate 30.

[0061] The working pressure of the booster airbag 5 is 1.5MPa. The booster airbag 5 is laid flat on the bottom surface of the cover plate 30 of the test pit through the bracket 50. The booster airbag 5 is composed of multiple airbag strips whose length is adapted to the length of the cover plate 30 of the test pit and connected in series. All the airbag strips are inflated through an inflation port opened on an airbag strip located in the middle.

[0062] The outlet of the air tank 6 is connected to the inflation port of the pressure bag 5 through an inflation pipe 60 that passes through an opening in the cover plate 30 of the test pit. The inflation pipe 60 is a corrugated pipe. The inlet of the air tank 6 is connected to the air compressor 6A.

[0063] Ballast blocks 7 are placed on the top surface of the cover plate 30 of the test pit. Ballast blocks 7 provide vertical ballast for the pressurization of the airbag.

[0064] The hoisting equipment 8 is positioned on the ground above the top surface of the test pit 3. The hoisting equipment should be capable of hoisting the water pump frame 21, submersible pump 2, sealing box 4, test pit cover 30, and ballast block 7.

[0065] The monitoring platform 9 is set up on the ground near the test pit 3. The monitoring platform 9 is connected to the submersible pump 2, the opening valve 43, the internal pressure sensor 44, the external pressure sensor 45, the flow sensor 25 and the air compressor 6A via signal lines.

[0066] The sealed box 4 is placed on the bottom plate of the test pit 3. The water level in the test pit 3 is close to the top, leaving room for the pressure-boosting airbag 5 to drain water, so that after the cover plate 30 is installed, the test pit 3 is almost full of water.

[0067] Since the pressure difference between the inside and outside of the bucket formed by pumping water during the bucket foundation sinking construction is closely related to the water depth, the submersible pump performance testing device of the present invention for bucket foundation sinking needs to simulate different water depth conditions during the testing of the submersible pump performance. If a pressurized airbag is not used, a test pit with a depth of 100m needs to be built to meet the testing of water depths within 100m. The water depth conditions are adjusted by controlling the water storage height in the test pit, which places high requirements on the depth of the test pit. The principle of simulating water depth using a pressurized airbag is as follows: When the water in the test pit is in full contact with the pressurized airbag (without gaps), taking the interface of full contact between the water and the pressurized airbag as the analysis object, static equilibrium analysis shows that the pressure of the water on the pressurized airbag is balanced with the pressure inside the pressurized airbag. Since the water pressure values ​​in all directions are the same at the same depth, the water pressure at this interface depth can be increased to the same level as the pressure in the pressurized airbag. Due to the incompressible nature of liquids, the pressurized water pressure (equal to the pressure in the pressurized airbag) at the interface of full contact between the water and the pressurized airbag can be transmitted to the bottom of the test pit. In summary, by adjusting the pressure of the pressurized airbag, the water pressure in the test pit can be adjusted to simulate different water depth conditions. The corresponding height requirement of the test pit is only slightly greater than the sum of the heights of the sealing box, water pump frame, and pressurized airbag, which can significantly reduce the construction requirements and cost of the test pit.

[0068] The performance testing method of the submersible pump for bucket foundation sinking construction of the present invention adopts the performance testing device of the submersible pump for bucket foundation sinking construction of the present invention. The testing method includes the following procedures: test preparation procedure S1 and test procedure S2.

[0069] The test preparation process S1 includes the following steps:

[0070] S11, install the opening valve 43, the internal pressure sensor 44 and the external pressure sensor 45 on the sealing box 4, and install the flow sensor 25 at the outlet of the submersible pump 2. Then, connect the submersible pump 2, the opening valve 43, the internal pressure sensor 44, the external pressure sensor 45, the flow sensor 25 and the air compressor 6A to the monitoring platform 9 and debug the connection lines. Then, install the submersible pump 2 in the water pump frame 21, and then place the water pump frame 21 as a whole on the top plate of the sealing box 4.

[0071] S12, under the condition that there is no water in the test pit 3, the sealing box 4 together with the submersible pump 2 is hoisted onto the bottom plate of the test pit 3 as a whole.

[0072] S13, initial water storage. Before water storage, fully open valve 43 to allow the gas in the sealed box 4 to be completely discharged and the sealed box 4 to be filled with water. The water level for this water storage should be such that the submersible pump 2 is submerged. Keep valve 43 fully open, turn on submersible pump 2 to pump water, and test whether submersible pump 2, internal pressure sensor 44, external pressure sensor 45 and flow sensor 25 are working properly.

[0073] S14, Secondary water storage: After ensuring the normal operation of submersible pump 2, internal pressure sensor 44, external pressure sensor 45 and flow sensor 25, continue to store water in test pit 3 until the water level reaches near cover plate 30. Test pit 3 is not filled with water this time, so as to reserve drainage volume for the pressurized airbag 5 fixed on the bottom surface of cover plate 30 when installing the cover plate 30 of the test pit later, so that the test pit 3 is nearly full of water after the cover plate 30 is installed.

[0074] S15, install the pressurized airbag 5 on the bottom surface of the cover plate 30 of the test pit, and then cover the top of the test pit 3 with the cover plate 30 so that the rubber water-stop pad 31 installed on the bottom edge of the cover plate 30 is in full contact with the ground to form an effective water stop. After the cover plate 30 is installed, the test pit 3 is nearly filled with water. Then, the inflation port of the pressurized airbag 5 is connected to the air storage tank 6 and the air compressor 6A in sequence through the inflation pipe 60.

[0075] S16, Ballast blocks 7 are placed on the top surface of the cover plate 30 of the test pit. The weight of the ballast blocks 7 is greater than the pressure generated by the maximum test water depth pressure within the area of ​​the cover plate 30. At this point, all test preparations are complete.

[0076] Test procedure S2 includes the following steps:

[0077] S21, the air compressor 6A and the air tank 6 are used to inflate the pressurized airbag 5 to the specified test pressure Pt, so that the pressure of the pressurized airbag 5 is always kept at Pt, thus completing the water depth environment simulation of Pt / 10 (the water pressure corresponding to each 1m water depth is 10kPa, and Pt / 10 is the water depth environment simulated by pressurizing the airbag).

[0078] S22, simulating the initial working conditions of the bucket foundation's pumping and settling, submersible pump 2 is started at its rated power, and valve 43 is fully opened. At this time, the pumping flow rate of submersible pump 2 is at its maximum, reaching its rated pumping capacity. During this stage, the settling resistance of the bucket foundation is close to its own weight, and only a small pressure difference between the inside and outside of the bucket is required to achieve settling. The pressure difference between the inside and outside of the bucket approaches 0. Valve 43 is kept fully open. After the pumping flow rate of submersible pump 2 and the pressure difference monitoring results stabilize, a set of pumping flow rate q of submersible pump 2 is recorded. 100％ Pressure difference ΔP between inside and outside the box 100％ =P 内100％ -P 外100％ ;P 内100％ The value monitored by pressure sensor 44 inside the chamber when the valve is 100% open; P 外100％ This is the value monitored by the external pressure sensor 45 when the valve is 100% open;

[0079] S23, simulating the gradual increase in penetration depth of the bucket foundation, the penetration resistance increases accordingly, requiring a certain pressure difference between the inside and outside of the bucket to achieve penetration. With submersible pump 2 operating at its rated power, the opening of valve 43 is adjusted to 80%, correspondingly reducing the pumping flow rate of submersible pump 2 and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate of submersible pump 2 and the pressure difference monitoring results stabilize, a set of pumping flow rate q of the submersible pump is recorded. 80％ Pressure difference ΔP between inside and outside the barrel 80％ =P 内 80％ -P 外80％ ;P 内80％ The value monitored by the pressure sensor inside the chamber when the valve is at 80% opening; P 外80％ This is the value monitored by the external pressure sensor when the valve is at 80% opening.

[0080] S24. Simulating the gradual increase in penetration depth of the simulated bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. With submersible pump 2 operating at its rated power, the opening of valve 43 is adjusted to 60%, further reducing the pumping flow rate of submersible pump 2 and further increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate of submersible pump 2 and the pressure difference monitoring results stabilize, a set of pumping flow rate q of submersible pump 2 is recorded. 60％ Pressure difference ΔP between inside and outside the box 60％ =P 内60％ -P 外60％ ;P 内60％ The value monitored by pressure sensor 44 inside the chamber when the valve is at 60% opening; P 外60％ The value monitored by the external pressure sensor 45 when the valve is at 60% opening.

[0081] S25, simulating the gradual increase in penetration depth of the bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. With submersible pump 2 operating at its rated power, the opening of the valve is adjusted to 40%, further reducing the pumping flow rate of submersible pump 2 and further increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate of submersible pump 2 and the pressure difference monitoring results stabilize, a set of pumping flow rate q of submersible pump 2 is recorded. 40％ Pressure difference ΔP between inside and outside the box 40％ =P 内40％ -P 外40％ ;P 内40％ The value monitored by pressure sensor 44 inside the chamber when the valve is at 40% opening; P 外40％ The value monitored by the external pressure sensor 45 when the valve is at 40% opening.

[0082] S26. Simulating the gradual increase in penetration depth of the simulated bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. With submersible pump 2 operating at its rated power, the opening of valve 43 is adjusted to 20%, further reducing the pumping flow rate of submersible pump 2 and further increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate of submersible pump 2 and the pressure difference monitoring results stabilize, a set of pumping flow rate q of submersible pump 2 is recorded. 20％ Pressure difference ΔP between inside and outside the box 20％ =P 内20％ -P 外20％ ;P 内20％ The value monitored by pressure sensor 44 inside the chamber when the valve is at 20% opening; P 外20％ The value monitored by the external pressure sensor 45 when the valve is at 20% opening.

[0083] S27, simulating the difficult settling condition of a bucket foundation under pumping conditions, with submersible pump 2 operating at its rated power, the opening of valve 43 is set to 0%, meaning valve 43 is completely closed. At this stage, the sum of the bucket foundation's self-weight and the pressure difference between the inside and outside of the bucket is insufficient to overcome the settling resistance. The pumping flow rate of submersible pump 2 approaches 0, and the absolute value of the pressure difference between the inside and outside of the bucket approaches its maximum value, Pt + Ps, where Ps is the difference between the absolute pressure inside the bucket and atmospheric pressure caused by pumping water, i.e., Ps is the suction force corresponding to the suction head of submersible pump 2. Although the submersible pump cannot detach the water below cover 30 from the bottom of cover 30 (achieving absolute vacuum), it will create a tendency for detachment, i.e., a certain degree of vacuum is formed through pumping. After the pumping flow rate of submersible pump 2 and the pressure difference between the inside and outside of the bucket stabilize, a set of data is recorded for the pumping flow rate q0 of submersible pump 2 and the pressure difference ΔP0 = P. 内0 -P 外0;P 内0 The value monitored by pressure sensor 44 inside the chamber when the valve is at 0 opening; P 外 0 represents the value monitored by the external pressure sensor 45 when the valve is at 0 opening.

[0084] S28, the pumping flow rate q of multiple submersible pumps 2 with the same water depth and valve 43 at different opening degrees and the pressure difference ΔP inside and outside the tank are plotted as a performance curve of the submersible pump for the sinking construction of the bucket foundation under a given water depth environment (see Figure 6a).

[0085] According to the accuracy requirements, multiple sets of opening valves 43 are added to monitor the pumping flow rate of submersible pump 2 and the pressure difference inside and outside the tank under different opening degrees. As the opening degree of the opening valve 43 decreases, the pumping flow rate of submersible pump 2 decreases, and the pressure difference inside and outside the tank increases, which is consistent with the actual working conditions of the bucket foundation sinking.

[0086] S29. By adjusting the inflation pressure Pt of the booster airbag 5, i.e. adjusting the water depth environment, repeat steps S22 to S28 to obtain the performance curves of the submersible pump 2 for bucket foundation sinking construction under a series of water depth environments (see Figure 6b). This provides a basis for the selection of submersible pumps for bucket foundation sinking construction. Under different water depth environments, the pressure inside and outside the tank is 0 when the valve is fully open, while the pressure difference inside and outside the tank increases with the increase of water depth when the valve is fully closed. This indicates that deep water is conducive to forming a larger pressure difference inside and outside the tank. However, it should also be noted that the maximum pressure difference inside and outside the tank that the submersible pump can obtain is not only related to the water depth, but is also limited by the capacity of the submersible pump itself (head, power, etc.). If the submersible pump itself is not capable enough, it may not be able to make full use of the water depth.

[0087] The above embodiments are for illustrative purposes only and are not intended to limit the invention. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the invention. Therefore, all equivalent technical solutions should also fall within the scope of the invention and should be defined by the claims.

Claims

1. A performance testing device for a submersible pump used in the sinking construction of a barrel foundation, comprising a sealed box, a submersible pump, a test pit, a pressurization airbag, an air storage tank, a ballast block, hoisting equipment, and a monitoring platform; characterized in that, The sealing box has a water inlet hole at the bottom of its side plate, and an opening valve is connected to the water inlet hole via a water inlet pipe. An internal pressure sensor is installed in the top plate of the sealing box, and an external pressure sensor is installed on the top surface of the top plate. A water outlet hole is provided on the top plate of the sealing box, and a water outlet pipe is welded to the water outlet hole. The submersible pump is installed inside the pump frame, which is placed on the top plate of the sealed box, so that the inlet of the submersible pump is connected to the outlet pipe of the sealed box; a flow sensor is installed at the outlet of the submersible pump. The test pit is located below ground level. The planar dimensions of the test pit are larger than those of the sealed box, and the depth of the test pit is greater than the sum of the height of the water pump frame and the height of the sealed box. The top of the test pit is covered with a cover plate. The planar dimensions of the cover plate are larger than those of the test pit, and a rubber water-stop pad is provided on the bottom edge of the cover plate to contact the ground. The pressurized airbag is laid flat on the bottom surface of the cover plate of the test pit via a bracket; The outlet of the air tank is connected to the inflation port of the pressurized air bag through an inflation pipe that passes through an opening in the cover plate, and the inlet of the air tank is connected to an air compressor. The ballast blocks are placed on the cover plate of the test pit; The hoisting equipment is positioned on the ground above the top surface of the test pit; The monitoring platform is located on the ground near the test pit. The monitoring platform is connected to the submersible pump, the opening valve, the internal pressure sensor, the external pressure sensor, the flow sensor, and the air compressor via signal lines. The sealed box is placed on the bottom plate of the test pit, and the water level in the test pit is close to the top, leaving room for drainage of the pressurized airbag, so that the test pit is almost full of water after the cover is installed.

2. The performance testing device for the submersible pump used in the sinking construction of a bucket foundation according to claim 1, characterized in that, The sealed box has a volume of not less than 1m³. 3 The sealing box is a cylindrical container; a lifting lug is provided on the top plate of the sealing box; a circumferential reinforcing rib and a radial reinforcing rib are provided on the bottom surface of the top plate and the top surface of the bottom plate of the sealing box, and a transverse reinforcing rib and a vertical reinforcing rib are provided on the inner surface of the side plate of the sealing box.

3. The performance testing device for the submersible pump used in the sinking construction of a bucket foundation according to claim 1, characterized in that, The pressurized airbag is composed of multiple airbag strips whose length is adapted to the length of the cover plate of the test pit and connected in series, and all airbag strips are inflated through an inflation port opened on an airbag strip located in the middle.

4. A performance testing method for a submersible pump used in the settlement construction of a bucket foundation, comprising the testing device for the performance of a submersible pump used in the settlement construction of a bucket foundation as described in claim 1, characterized in that, The test method The process includes the following steps: test preparation step S1 and test step S2; The test preparation process S1 includes the following steps: S11, install the opening valve, the pressure sensor inside the box and the pressure sensor outside the box on the sealed box, and install the flow sensor at the outlet of the submersible pump. Then, connect the submersible pump, the opening valve, the pressure sensor inside the box, the pressure sensor outside the box, the flow sensor and the air compressor to the monitoring platform and debug the connection lines. Then, install the submersible pump in the water pump frame, and then place the water pump frame as a whole on the top plate of the sealed box. S12, under the condition that there is no water in the test pit, the sealing box and the submersible pump are hoisted together onto the bottom plate of the test pit; S13, Initial water filling: Before filling, fully open the valve to allow the gas in the sealed box to be completely discharged and the sealed box to be filled with water. The water level should be enough to submerge the submersible pump. Keep the valve fully open, start the submersible pump to pump water, and test whether the submersible pump, the pressure sensor inside the box, the pressure sensor outside the box, and the flow sensor are working properly. S14, Secondary water storage: After ensuring the submersible pump, internal pressure sensor, external pressure sensor and flow sensor are working properly, continue to store water in the test pit until the water level reaches near the cover plate. S15, Install a pressurized airbag on the bottom surface of the cover plate of the test pit, and then cover the top of the test pit with the cover plate so that the rubber water-stop pad installed on the bottom edge of the cover plate is in full contact with the ground to form an effective water stop. After the cover plate is installed, the test pit is nearly filled with water. Then, the inflation port of the pressurized airbag is connected to the air tank and the air compressor in sequence through the inflation pipe. S16, place ballast blocks on the top surface of the cover plate of the test pit. The weight of the ballast blocks is greater than the pressure generated by the maximum test water depth within the area of ​​the cover plate. At this point, all test preparations are complete. The experimental procedure S2 includes the following steps: S21, the pressurization airbag is inflated by the air compressor-air tank and pressurized to the specified test pressure Pt, so that the pressure of the pressurization airbag is always kept at Pt, that is, the water depth environment simulation of Pt / 10 is completed. S22, simulating the initial working conditions of the bucket foundation's pumping and settling, starts the submersible pump at its rated power and fully opens the valve. At this point, the submersible pump's flow rate is at its maximum, reaching its rated pumping capacity. During this stage, the settling resistance of the bucket foundation is close to its own weight, requiring only a small pressure difference between the inside and outside of the bucket to achieve settling. The pressure difference between the inside and outside of the bucket approaches zero. The valve remains fully open. After the pumping flow rate and the pressure difference between the inside and outside of the bucket stabilize, a set of pumping flow rate q is recorded. 100％ Pressure difference ΔP between inside and outside the box 100％ =P 内100％ -P 外100％ ;P 内100％ The value monitored by the pressure sensor inside the chamber when the valve is 100% open; P 外100％ This is the value monitored by the external pressure sensor when the valve is 100% open; S23, simulating the gradual increase in penetration depth of a bucket foundation, the penetration resistance increases accordingly, requiring a certain pressure difference between the inside and outside of the bucket to achieve penetration. With the submersible pump operating at its rated power, the opening of the valve is adjusted to 80%, correspondingly reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 80％ Pressure difference ΔP between inside and outside the box 80％ =P 内80％ -P 外80％ ;P 内 80％ The value monitored by the pressure sensor inside the chamber when the valve is at 80% opening; P 外80％ This is the value monitored by the external pressure sensor when the valve is at 80% opening. S24, simulating the gradual increase in penetration depth of the bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. While maintaining the submersible pump at its rated power, the opening of the valve is adjusted to 60%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 60％ Pressure difference ΔP between inside and outside the barrel 60％ =P 内 60％ -P 外60％ ;P 内60％ The value monitored by the pressure sensor inside the chamber when the valve is at 60% opening; P 外60％ This is the value monitored by the external pressure sensor when the valve is at 60% opening. S25, simulating the gradual increase in penetration depth of a bucket foundation, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. With the submersible pump operating at its rated power, the opening of the valve is adjusted to 40%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 40％ Pressure difference ΔP between inside and outside the box 40％ =P 内 40％ -P 外40％ ;P 内40％ The value monitored by the pressure sensor inside the chamber when the valve is at 40% opening; P 外40％ This is the value monitored by the external pressure sensor when the valve is at 40% opening. S26. Simulating a bucket foundation, as the penetration depth gradually increases, the penetration resistance increases accordingly, requiring a larger pressure difference between the inside and outside of the bucket to achieve penetration. Maintaining the submersible pump at its rated power, the opening of the valve is adjusted to 20%, further reducing the pumping flow rate and increasing the absolute value of the pressure difference between the inside and outside of the bucket. After the pumping flow rate and the pressure difference monitoring results stabilize, a set of pumping flow rate q is recorded. 20％ Pressure difference ΔP between inside and outside the barrel 20％ =P 内 20％ -P 外20％ ;P 内20％ The value monitored by the pressure sensor inside the chamber when the valve is at 20% opening; P 外20％ This is the value monitored by the external pressure sensor when the valve is at 20% opening. S27, simulating the difficult settling condition of a bucket foundation under pumping conditions, with the submersible pump operating at its rated power, the opening of the valve is set to 0%, meaning the valve is completely closed. At this stage, the sum of the bucket foundation's self-weight and the pressure difference between the inside and outside of the bucket is still insufficient to overcome the settling resistance. The submersible pump's flow rate approaches 0, and the absolute value of the pressure difference between the inside and outside of the bucket approaches its maximum value, Pt + Ps. Ps is the difference between the absolute pressure inside the bucket and atmospheric pressure caused by the submersible pump pumping water; that is, Ps is the suction force corresponding to the pump's suction head. After the submersible pump's flow rate and the pressure difference between the inside and outside of the bucket stabilize, a set of data is recorded for the submersible pump's flow rate q0 and the pressure difference ΔP0 = P. 内0 -P 外0 ;P 内0 The value monitored by the pressure sensor inside the chamber when the valve is at 0 opening; P 外0 This is the value monitored by the external pressure sensor when the valve is at 0 opening. S28, plot the relationship between the pumping flow rate q and the pressure difference ΔP inside and outside the tank of multiple submersible pumps with the same water depth and valve opening degree under different opening degrees as a performance curve of the submersible pump under a given water depth environment. S29, adjust the inflation pressure Pt of the booster airbag, i.e. adjust the water depth environment, repeat steps S22 to S28 to obtain the performance curve of the submersible pump under a series of water depth environments.

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