Performance testing device and method for submersible pump used in bucket foundation sinking construction

Abstract

The application discloses a performance testing device and method for a submersible pump used in barrel type foundation sinking construction, and the testing device comprises a sealed box, a submersible pump, a test pit, a pressurized air bag, a gas storage tank, a ballast block and a monitoring platform. The side plate of the sealed box is provided with an opening connected with an opening degree valve; a box inner pressure sensor is arranged on the top plate of the sealed box, and a box outer pressure sensor is arranged on the top surface of the top plate; the submersible pump is arranged in a water pump frame arranged on the top plate of the sealed box, so that the water inlet of the submersible pump is connected with the water outlet pipe of the sealed box; a flow sensor is arranged on the water outlet of the submersible pump; the top of the test pit is covered with a cover plate; the pressurized air bag is arranged on the bottom surface of the cover plate; the gas outlet of the gas storage tank is connected with the inflation opening of the pressurized air bag; the ballast block is arranged on the cover plate; and the monitoring platform is arranged on the ground near the test pit. The sealed box is arranged on the bottom plate of the test pit, and the water level in the test pit is close to the top. The application can provide quantitative support for the selection of the submersible pump used in barrel type foundation sinking construction.

Description

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 engineering 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 difference"). Under the action of this pressure difference, the sinking resistance is overcome, and the foundation is installed (see...). Figure 1a and Figure 1b Submersible pumps are core equipment in the installation of bucket foundations, but their 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 conventional submersible pumps 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] The most concerned parameter for the submersible pump used for the sinking of the bucket foundation is the relationship between the flow and the pressure difference between the inside and outside of the bucket at a given power (rotational speed), rather than the relationship between the lift and the flow. In addition, since the pressure difference between the inside and outside of the bucket is related to the water depth, the influence of the water depth needs to be considered. At present, no pump performance curve graph suitable for the selection of the submersible pump used for the sinking of the bucket foundation is provided by the submersible pump manufacturers, and there is also no special detection device for measuring the relationship between the flow and the pressure difference between the inside and outside of the bucket. SUMMARY

[0006] The present application aims to overcome the defects of the prior art and provide a performance testing device and method for a submersible pump used for the sinking of a bucket foundation, which can provide quantitative support for the selection of the submersible pump used for the sinking of the bucket foundation.

[0007] A technical solution for achieving the object of the present application is as follows: a performance testing device for a submersible pump used for the sinking of a bucket foundation, comprising a sealed box, a submersible pump, a test pit, a pressurized air bag, an air storage tank, a ballast block, hoisting equipment and a monitoring platform; wherein,

[0008] A sealed box water inlet hole is formed in the bottom of the side plate of the sealed box, and an opening degree valve is connected to the sealed box water inlet hole through a sealed box water inlet pipe; a box internal pressure sensor is installed on the top plate of the sealed box; a box external pressure sensor is installed on the top surface of the top plate of the sealed box; a sealed box water outlet hole is formed in the top plate of the sealed box, and a sealed box water outlet pipe is welded to the sealed box water outlet hole;

[0009] The submersible pump is installed in a water pump frame, and the water pump frame is arranged on the top plate of the sealed box, so that the water inlet of the submersible pump is connected to the sealed box water outlet pipe; a flow sensor is installed on the water outlet of the submersible pump;

[0010] The test pit is arranged below the ground, the planar size of the test pit is greater than the planar size 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 size of the cover plate is greater than the planar size of the test pit, and a circle of rubber water stop pads in contact with the ground are arranged on the edge bottom surface of the cover plate;

[0011] The pressurized air bag is laid flat on the bottom surface of the cover plate of the test pit through a support;

[0012] The air outlet of the air storage tank is connected to the air inlet of the pressurized air bag through an inflation pipe arranged in the hole of the cover plate, and the air inlet of the air storage tank is connected to an air compressor;

[0013] The ballast block is placed on the cover plate of the test pit;

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

[0015] The monitoring platform is arranged on the ground near the test pit and is connected with the submersible pump, the opening valve, the in-tank pressure sensor, the out-tank pressure sensor, the flow sensor and the air compressor through signal lines respectively;

[0016] The sealed tank is placed on the bottom plate of the test pit, the water level in the test pit is close to the top, and a drainage volume is reserved for the pressurized air bag, so that the test pit is close to being filled with water after the cover plate is installed.

[0017] The performance testing device for the submersible pump used in the sinking construction of the bucket foundation, wherein the sealed tank is a cylinder with a volume of not less than 1 m 3 ; the top plate of the sealed tank is provided with lifting lugs; the bottom surface of the top plate and the top surface of the bottom plate are respectively provided with annular and radial reinforcing ribs; and the inner surface of the side plate is provided with transverse and vertical reinforcing ribs.

[0018] The performance testing device for the submersible pump used in the sinking construction of the bucket foundation, wherein the pressurized air bag is composed of a plurality of air bag strips with lengths adapted to the length of the cover plate of the test pit and connected in series, and all the air bag strips are inflated through an inflation opening formed on a middle air bag strip.

[0019] Another technical solution for achieving the object of the present application is a performance testing method for a submersible pump used in the sinking construction of a bucket foundation, which adopts the performance testing device for the submersible pump used in the sinking construction of the bucket foundation, and the testing method comprises the following processes: a test preparation process S1 and a test process S2.

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

[0021] S11, installing the opening valve, the in-tank pressure sensor and the out-tank pressure sensor on the sealed tank, installing the flow sensor at the water outlet of the submersible pump, electrically connecting the submersible pump, the opening valve, the in-tank pressure sensor, the out-tank pressure sensor, the flow sensor and the air compressor to the monitoring platform, debugging the connection line, installing the submersible pump in the water pump frame, and then placing the water pump frame on the top plate of the sealed tank;

[0022] S12, hoisting the sealed tank together with the submersible pump to the bottom plate of the test pit under the condition that there is no water in the test pit;

[0023] S13, initial water storage, completely opening the opening valve before water storage, completely discharging the gas in the sealed tank, filling the sealed tank with water, stopping the opening valve, starting the submersible pump to pump water, and testing whether the submersible pump, the in-tank pressure sensor, the out-tank pressure sensor and the flow sensor work normally;

[0024] S14, after ensuring the normal operation of the submersible pump, the pressure sensor inside the tank, the pressure sensor outside the tank and the flow sensor, continue to store water in the test pit until the water level reaches the vicinity of the cover plate;

[0025] S15, install the pressurized air bag on the bottom surface of the cover plate of the test pit, then cover the cover plate on the top of the test pit, make the rubber water stop pad installed on the edge of the bottom surface of the cover plate fully contact with the ground to form effective water stop, after the cover plate is installed, make the test pit nearly full of water, then connect the inflation port of the pressurized air bag with the gas storage tank and the air compressor in sequence through the inflation pipe;

[0026] S16, stack the 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 in the area range of the cover plate, thus the whole test preparation is completed;

[0027] The test procedure S2 comprises the following steps:

[0028] S21, inflate the pressurized air bag through the air compressor-gas storage tank, press to the specified test pressure Pt, so that the pressure of the pressurized air bag is always kept as Pt, that is, the water depth environment simulation of Pt / 10 is completed;

[0029] S22, simulate the initial working condition of the bucket foundation during the process of pumping sinking, start the submersible pump at the rated power and open the opening valve completely, at this time, the pumping flow of the submersible pump is maximum, reaches the rated pumping capacity of the submersible pump, the sinking resistance of the bucket foundation is similar to the weight of the bucket foundation at this stage, only a very small pressure difference between the inside and outside of the tank is needed to realize sinking, the pressure difference between the inside and outside of the tank tends to 0, keep the opening valve in the fully open state, after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, record a group of pumping flow q 100% and the pressure difference ΔP 100% between the inside and outside of the tank; 内100% -P 外100% ; P 内100% is the value monitored by the pressure sensor inside the tank when the opening valve is at 100% opening degree; P 外100% is the value monitored by the pressure sensor outside the tank when the opening valve is at 100% opening degree;

[0030] S23, simulate the working condition that the sinking resistance increases with the increase of the sinking depth of the bucket foundation, a certain pressure difference between the inside and outside of the tank is needed to realize sinking, keep the submersible pump in the state of pumping at the rated power, adjust the opening degree of the opening valve to 80%, the pumping flow of the submersible pump decreases and the absolute value of the pressure difference between the inside and outside of the tank increases; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, record a group of pumping flow q 80% and the pressure difference ΔP 80% between the inside and outside of the tank; 内80% -P 外80% ;内80% P is the value monitored by the inside tank pressure sensor when the opening degree of the opening degree valve is 80%; P 外80% P is the value monitored by the outside tank pressure sensor when the opening degree of the opening degree valve is 80%; P

[0031] S24, the bucket foundation is simulated to gradually increase with the sinking depth, the sinking resistance correspondingly increases, a larger pressure difference between the inside and outside of the bucket is needed to realize the sinking working condition, the opening degree of the opening degree valve is adjusted to 60% under the condition that the submersible pump is in the state of pumping water at the rated power, the pumping flow of the submersible pump is further reduced, and the absolute value of the pressure difference between the inside and outside of the tank is further increased; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a group of pumping flow q 60% and the pressure difference ΔP 60% =P 内60% -P 外60% ; P 内60% P is the value monitored by the inside tank pressure sensor when the opening degree of the opening degree valve is 60%; P 外60% P is the value monitored by the outside tank pressure sensor when the opening degree of the opening degree valve is 60%; P

[0032] S25, the bucket foundation is simulated to gradually increase with the sinking depth, the sinking resistance correspondingly increases, a larger pressure difference between the inside and outside of the bucket is needed to realize the sinking working condition, the opening degree of the opening degree valve is adjusted to 40% under the condition that the submersible pump is in the state of pumping water at the rated power, the pumping flow of the submersible pump is further reduced, and the absolute value of the pressure difference between the inside and outside of the tank is further increased; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a group of pumping flow q 40% and the pressure difference ΔP 40% =P 内40% -P 外40% ; P 内40% P is the value monitored by the inside tank pressure sensor when the opening degree of the opening degree valve is 40%; P 外40% P is the value monitored by the outside tank pressure sensor when the opening degree of the opening degree valve is 40%; P

[0033] S26, the bucket foundation is simulated to gradually increase with the sinking depth, the sinking resistance correspondingly increases, a larger pressure difference between the inside and outside of the bucket is needed to realize the sinking working condition, the opening degree of the opening degree valve is adjusted to 20% under the condition that the submersible pump is in the state of pumping water at the rated power, the pumping flow of the submersible pump is further reduced, and the absolute value of the pressure difference between the inside and outside of the tank is further increased; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a group of pumping flow q 20% and the pressure difference ΔP 20% =P 内20% -P 外20% ; P 内20% P is the value monitored by the inside tank pressure sensor when the opening degree of the opening degree valve is 20%; P外20% P0 is the value monitored by the tank internal pressure sensor when the opening degree valve is at 0 opening degree;

[0034] S27, simulate the working condition of difficult sinking of the bucket foundation, keep the submersible pump in the state of pumping at rated power, set the opening degree of the opening degree valve to 0%, that is, the opening degree valve is completely closed, the sum of the self-weight of the bucket foundation and the pressure difference between the inside and outside of the bucket is still insufficient to overcome the sinking resistance, the pumping flow of the submersible pump tends to 0, and the absolute value of the pressure difference between the inside and outside of the tank tends to the maximum value Pt+Ps, Ps is the difference between the absolute pressure in the tank and the atmospheric pressure caused by the pumping of the submersible pump, that is, Ps is the suction force corresponding to the suction stroke of the submersible pump; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a set of pumping flow q0 of the submersible pump and the pressure difference ΔP0 between the inside and outside of the tank P 内0 -P 外0 ;P 内0 P0 is the value monitored by the tank internal pressure sensor when the opening degree valve is at 0 opening degree; 外0 P0 is the value monitored by the tank internal pressure sensor when the opening degree valve is at 0 opening degree;

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

[0036] S29, adjust the inflation pressure Pt of the pressure-increasing air bag, that is, adjust the water depth environment, repeat steps S22 to S28 to obtain the performance curves of the submersible pump under a series of water depth environments.

[0037] The performance testing device and method for the submersible pump used in the sinking construction of the bucket foundation have the following characteristics:

[0038] 1. The existing submersible pump used in the sinking construction of the bucket foundation lacks quantitative support of performance indicators of the submersible pump, and the testing device and method of the present application provide quantitative support for the selection of the submersible pump used in the sinking construction of the bucket foundation;

[0039] 2. The conventional submersible pump performance testing device cannot simulate pumping from a sealed space, and the present application realizes the simulation of pumping from a sealed space by setting a sealed tank, which is consistent with the actual working condition of the sinking of the bucket foundation;

[0040] 3. The conventional submersible pump performance testing device only tests the inlet and outlet pressures of the submersible pump, and the testing method of the present application tests the internal and external pressures of the sealed tank connected to the submersible pump, which is consistent with the actual working condition of the sinking of the bucket foundation;

[0041] 4. The conventional submersible pump performance testing device has no water depth simulation system, and the testing method of the present application uses a pressurized air bag to simulate different water depth environments without the need of a deep pit to simulate the influence of different water depths. BRIEF DESCRIPTION OF DRAWINGS

[0042] Figure 1a is a state diagram of a conventional bucket type foundation sinking;

[0043] Figure 1b is another state diagram of a conventional bucket type foundation sinking;

[0044] Figure 2 is a structural schematic diagram of a conventional submersible pump performance testing device;

[0045] Figure 3 is a structural schematic diagram of a submersible pump performance testing device for bucket type foundation sinking construction of the present application;

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

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

[0048] Figure 5a is a state diagram when step S12 of the testing method of the present application is performed;

[0049] Figure 5b is a state diagram when step S13 of the testing method of the present application is performed;

[0050] Figure 5c is a state diagram when step S14 of the testing method of the present application is performed;

[0051] Figure 5d is a state diagram when step S15 of the testing method of the present application is performed;

[0052] Figure 5e is a state diagram when step S16 of the testing method of the present application is performed;

[0053] Figure 5f is a state diagram when step S21 of the testing method of the present application is performed;

[0054] Figure 6a is a performance curve diagram of a submersible pump obtained when step S28 of the testing method of the present application is performed;

[0055] Figure 6b is a performance curve diagram of a submersible pump obtained when step S29 of the testing method of the present application is performed. DETAILED DESCRIPTION

[0056] The application will be further described below 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 bucket foundation sinking construction of the application comprises a testing pit 3, a sealing box 4, a submersible pump 2, a pressurized air bag 5, a gas storage tank 6, a ballast block 7, hoisting equipment 8 and a monitoring platform 9.

[0058] The sealing box 4 is a cylinder with a volume not less than 1m 3 ; the top plate of the sealing box 4 is provided with lifting lugs 40; the bottom surface of the top plate and the top surface of the bottom plate of the sealing box 4 are respectively provided with annular and radial reinforcing ribs; the inner surface of the side plate of the sealing box 4 is provided with reinforcing ribs 46, which include transverse and vertical reinforcing ribs; the bottom of the side plate of the sealing box 4 is provided with a sealing box water inlet hole, and a sealing box water inlet pipe 41 is welded on the sealing box water inlet hole; the other end of the sealing box water inlet pipe 41 is connected with an opening valve 43 through a flange; a box-in pressure sensor 44 is installed on the top plate of the sealing box 4 through a hole; a box-out 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 formed on the top plate of the sealing box 4, and a sealing box water outlet pipe 42 is welded in the sealing box water outlet hole. The measuring range of the box-in pressure sensor 44 and the box-out pressure sensor 45 is -0.1-2MPa, and the measuring accuracy is 0.1%.

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

[0060] The testing pit 3 is arranged below the ground, the plane of the testing pit 3 is rectangular, the plane size of the testing pit 3 is greater than the plane size of the sealing box 4, and the depth of the testing 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 testing pit 3 is covered with a cover plate 30, the plane size of the cover plate 30 is greater than the plane size of the testing pit 3, and a circle of rubber water stop pads 31 in contact with the ground is arranged on the edge bottom surface of the cover plate 30 of the testing pit; lifting lugs 32 are arranged on the top surface of the cover plate 30 of the testing pit.

[0061] The working pressure of the pressurized air bag 5 is 1.5MPa, and the pressurized air bag 5 is laid on the bottom surface of the cover plate 30 of the testing pit through a support 50; the pressurized air bag 5 is composed of a plurality of air bag strips with lengths adapted to the length of the cover plate 30 of the testing pit and connected in series, and all the air bag strips are inflated through an inflation port formed on a middle air bag strip.

[0062] The air outlet of the gas tank 6 is connected with the air inlet of the pressure air bag 5 through an air filling pipe 60 arranged in an opening of the cover plate 30 of the test pit, and the air filling pipe 60 is a corrugated pipe. The air inlet of the gas tank 6 is connected with the air compressor 6A.

[0063] The ballast block 7 is placed on the top surface of the cover plate 30 of the test pit, and the ballast block 7 provides vertical ballast for the pressure of the pressure air bag.

[0064] The hoisting device 8 is arranged on the ground above the top surface of the test pit 3. The capacity of the hoisting device should meet the hoisting requirements of the water pump frame 21, the submersible pump 2, the sealing box 4, the cover plate 30 of the test pit and the ballast block 7.

[0065] The monitoring platform 9 is arranged on the ground near the test pit 3, and the monitoring platform 9 is connected with the submersible pump 2, the opening valve 43, the in-box pressure sensor 44, the out-box pressure sensor 45, the flow sensor 25 and the air compressor 6A through signal lines.

[0066] The sealing box 4 is placed on the bottom plate of the test pit 3, and the water level in the test pit 3 is close to the top. A drainage volume is reserved for the pressure air bag 5, so that the test pit 3 is close to being filled with water after the cover plate 30 is installed.

[0067] Since the pressure difference between the inside and outside of the barrel caused by pumping water during the sinking construction of the barrel foundation is closely related to the water depth, the performance testing device for the submersible pump for the sinking of the barrel foundation needs to simulate different water depth conditions during the performance testing of the submersible pump. If the pressure air bag is not used, a test pit with a depth of 100 m needs to be built to meet the testing of the water depth within 100 m, and the water depth condition is adjusted by controlling the water storage height in the test pit, so that the depth requirement of the test pit is higher. The principle of simulating the water depth by the pressure air bag is as follows: when the water body in the test pit is in full contact (without gap) with the pressure air bag, taking the full contact interface between the water body and the pressure air bag as the analysis object, it can be known from the static force balance analysis that the pressure of the water body on the pressure air bag is balanced with the pressure in the pressure air bag, and it can be known from the fact that the water pressure values in all directions at the same depth are the same that the water pressure at the interface depth can be increased to be the same as the pressure of the pressure air bag. It can be known from the incompressibility of the liquid that the water pressure (the value is equal to the pressure of the pressure air bag) after the pressure increase at the full contact interface between the water body and the pressure air bag can be transmitted to the bottom of the test pit. In summary, by adjusting the pressure of the pressure air bag, the water pressure in the test pit is adjusted to simulate different water depth conditions, and the height requirement of the corresponding test pit is only slightly greater than the sum of the heights of the sealing box, the water pump frame and the pressure air bag, so that the construction requirement and cost of the test pit can be greatly reduced.

[0068] The performance testing method of the submersible pump for the sinking construction of the barrel foundation of the present application adopts the performance testing device for the submersible pump for the sinking construction of the barrel foundation of the present application, and the testing method includes the following processes: a test preparation process S1 and a test process S2.

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

[0070] S11, install the opening valve 43, the in-tank pressure sensor 44 and the out-tank pressure sensor 45 on the sealed tank 4, install the flow sensor 25 at the water outlet of the submersible pump 2, electrically connect the submersible pump 2, the opening valve 43, the in-tank pressure sensor 44, the out-tank pressure sensor 45, the flow sensor 25 and the air compressor 6A to the monitoring platform 9, debug the connection line, install the submersible pump 2 in the water pump frame 21, and then place the water pump frame 21 on the top plate of the sealed tank 4;

[0071] S12, under the condition that there is no water in the test pit 3, hoist the sealed tank 4 together with the submersible pump 2 to the bottom plate of the test pit 3;

[0072] S13, initial water storage, open the opening valve 43 completely before water storage, so as to facilitate the complete discharge of the gas in the sealed tank 4 and the filling of the sealed tank 4 with water, the water level of this time of water storage is to submerge the submersible pump 2, keep the opening valve 43 completely open, start the submersible pump 2 to pump water, and test whether the submersible pump 2, the in-tank pressure sensor 44, the out-tank pressure sensor 45 and the flow sensor 25 work normally;

[0073] S14, secondary water storage, after ensuring that the submersible pump 2, the in-tank pressure sensor 44, the out-tank pressure sensor 45 and the flow sensor 25 work normally, continue to store water in the test pit 3 until the water level reaches the vicinity of the cover plate 30, this time of water storage does not fill the test pit 3 with water, so as to reserve the drainage volume for the pressurized air bag 5 fixed on the bottom surface of the cover plate 30, so as to realize that the test pit 3 is close to being filled with water after the installation of the cover plate 30;

[0074] S15, install the pressurized air bag 5 on the bottom surface of the cover plate 30 of the test pit, cover the cover plate 30 on the top of the test pit 3, make the rubber water stop pad 31 installed on the bottom surface edge of the cover plate 30 fully contact with the ground to form effective water stop, make the test pit 3 close to being filled with water after the installation of the cover plate 30, and then sequentially connect the inflation port of the pressurized air bag 5 with the gas storage tank 6 and the air compressor 6A through the inflation pipe 60;

[0075] S16, stack the ballast blocks 7 on the top surface of the cover plate 30 of the test pit, the gravity of the ballast blocks 7 is greater than the pressure generated by the maximum test water depth pressure in the area range of the cover plate 30, and thus the whole test preparation is completed;

[0076] The test process S2 includes the following steps:

[0077] S21, inflate the pressure chamber 5 through the air compressor 6A and the air tank 6, pressurize to the specified test pressure Pt, keep the pressure of the pressure chamber 5 as Pt, that is, complete the water depth environment simulation of Pt / 10 (the water pressure corresponding to every 1m water depth is 10kPa, Pt / 10 is the water depth environment simulated by the pressure chamber);

[0078] S22, simulate the initial working condition of the bucket foundation sinking, start the submersible pump 2 at the rated power, and completely open the opening valve 43, at this time the water pumping flow of the submersible pump 2 is maximum, reaches the rated water pumping flow of the submersible pump 2, the sinking resistance of the bucket foundation is close to the weight of the bucket foundation at this stage, only a very small pressure difference between the inside and outside of the tank is needed to realize sinking, the pressure difference between the inside and outside of the tank tends to 0, keep the opening valve 43 in the completely open state, after the water pumping flow of the submersible pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, record a group of water pumping flow q 100% and the pressure difference between the inside and outside of the tank ΔP 100% =P 内100% -P 外100% ; P 内100% is the value monitored by the inside tank pressure sensor 44 when the opening valve is at 100% opening degree; P 外100% is the value monitored by the outside tank pressure sensor 45 when the opening valve is at 100% opening degree;

[0079] S23, simulate the working condition that the sinking resistance of the bucket foundation increases with the gradual increase of the sinking depth, a certain pressure difference between the inside and outside of the tank is needed to realize sinking, keep the submersible pump 2 in the water pumping state at the rated power, adjust the opening degree of the opening valve 43 to 80%, the water pumping flow of the submersible pump 2 decreases correspondingly, and the absolute value of the pressure difference between the inside and outside of the tank increases; after the water pumping flow of the submersible pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, record a group of water pumping flow q 80% and the pressure difference between the inside and outside of the tank ΔP 80% =P 内80% -P 外80% ; P 内80% is the value monitored by the inside tank pressure sensor when the opening valve is at 80% opening degree; P 外80% is the value monitored by the outside tank pressure sensor when the opening valve is at 80% opening degree;

[0080] S24, simulate the working condition that the sinking resistance of the bucket foundation increases with the gradual increase of the sinking depth, a larger pressure difference between the inside and outside of the tank is needed to realize sinking, keep the submersible pump 2 in the water pumping state at the rated power, adjust the opening degree of the opening valve 43 to 60%, the water pumping flow of the submersible pump 2 further decreases, and the absolute value of the pressure difference between the inside and outside of the tank further increases, after the water pumping flow of the submersible pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, record a group of water pumping flow q 60% and the pressure difference between the inside and outside of the tank ΔP 60% =P内60% P 外60% ; P 内60% P 外60% P

[0081] S25, the bucket foundation gradually increases with the sinking depth, the sinking resistance increases accordingly, and a larger pressure difference between the inside and outside of the bucket is needed to realize the sinking working condition. The opening of the opening valve is adjusted to 40% while keeping the submersible pump 2 in the state of pumping water at the rated power. The pumping flow of the submersible pump 2 is further reduced, and the absolute value of the pressure difference between the inside and outside of the tank is further increased. After the pumping flow of the submersible pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a group of pumping flow q 40% and the pressure difference between the inside and outside of the tank ΔP 40% = P 内40% - P 外40% ; P 内40% P 外40% P

[0082] S26, the bucket foundation gradually increases with the sinking depth, the sinking resistance increases accordingly, and a larger pressure difference between the inside and outside of the bucket is needed to realize the sinking working condition. The opening of the opening valve 43 is adjusted to 20% while keeping the submersible pump 2 in the state of pumping water at the rated power. The pumping flow of the submersible pump 2 is further reduced, and the absolute value of the pressure difference between the inside and outside of the tank is further increased. After the pumping flow of the submersible pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a group of pumping flow q 20% and the pressure difference between the inside and outside of the tank ΔP 20% = P 内20% - P 外20% ; P 内20% P 外20% P

[0083] S27, simulate the difficult working condition of bucket foundation sinking, keep the submerged pump 2 in the state of pumping at rated power, set the opening of the opening valve 43 to 0%, that is, the opening valve 43 is completely closed, the sum of the self weight of the bucket foundation and the pressure difference between the inside and outside of the bucket is still not enough to overcome the sinking resistance, the pumping flow of the submerged pump 2 tends to 0, and the absolute value of the pressure difference between the inside and outside of the tank tends to the maximum value Pt+Ps, wherein Ps is the difference between the absolute pressure in the tank and the atmospheric pressure caused by the pumping of the submerged pump 2, that is, Ps is the suction force corresponding to the suction lift of the submerged pump 2; although the submerged pump cannot separate the water body at the lower part of the cover plate 30 from the bottom of the cover plate 30 by pumping (reach absolute vacuum), it will form a tendency to separate, that is, a certain degree of vacuum is formed by pumping, after the pumping flow of the submerged pump 2 and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a set of pumping flow q0 of the submerged pump 2 and pressure difference ΔP0=P 内0 -P 外0 ;P 内0 is the value monitored by the pressure sensor 44 in the tank at 0 opening of the opening valve; P 外 0 is the value monitored by the pressure sensor 45 outside the tank at 0 opening of the opening valve;

[0084] S28, draw a performance curve of the submerged pump for bucket foundation sinking construction at a given water depth environment (see Figure 6a ) by using multiple sets of pumping flow q of the submerged pump 2 and pressure difference ΔP between the inside and outside of the tank of the opening valve 43 at different opening values at the same water depth;

[0085] According to the accuracy requirement, multiple sets of monitoring data of the pumping flow of the submerged pump 2 and the pressure difference between the inside and outside of the tank corresponding to the opening valve 43 at different opening values are added; with the opening value of the opening valve 43 decreasing, the pumping flow of the submerged pump 2 decreases, and the pressure difference between the inside and outside of the tank increases, which is consistent with the actual working condition of the bucket foundation sinking;

[0086] S29, by adjusting the inflation pressure Pt of the pressure boosting air bag 5, that is, adjusting the water depth environment, repeat steps S22 to S28 to obtain the performance curve of the submerged pump for bucket foundation sinking construction at a series of water depth environments (see Figure 6b ), which provides a basis for the selection of the submerged pump for bucket foundation sinking construction, wherein at different water depth environments, the pressure inside and outside the tank is 0 when the opening valve is fully opened, and the pressure difference between the inside and outside of the tank increases with the increase of the water depth when the opening valve is fully closed, which indicates that deep water is conducive to forming a larger pressure difference between the inside and outside of the bucket, but it should be pointed out that the maximum pressure difference between the inside and outside of the bucket that can be obtained by the pumping of the submerged pump is not only related to the water depth, but also limited by the capacity (head, power, etc.) of the submerged pump itself, if the capacity of the submerged pump itself is insufficient, it may not be able to fully utilize the water depth.

[0087] The above examples are only for illustrating the present application, and are not intended to limit the present application. Those skilled in the art can make various changes or modifications without departing from the spirit and scope of the present application. Therefore, all equivalent technical solutions should belong to the scope of the present application, which should be defined by the claims.

Claims

1. A performance testing device for a submersible pump used in a caisson foundation sinking construction, comprising a sealed box, a submersible pump, a test pit, a pressurized air bag, an air storage tank, a ballast block, a hoisting device and a monitoring platform; characterized in that, a sealed box water inlet hole is formed in the bottom of the side plate of the sealed box, and a sealed box water inlet pipe is connected to the sealed box water inlet hole through an opening degree valve; a box internal pressure sensor is installed on the top plate of the sealed box, a box external pressure sensor is installed on the top surface of the top plate of the sealed box; a sealed box water outlet hole is formed in the top plate of the sealed box, and a sealed box water outlet pipe is welded to the sealed box water outlet hole; the submersible pump is installed in a water pump frame, which is placed on the top plate of the sealed box, so that the water inlet of the submersible pump is connected to the sealed box water outlet pipe; a flow sensor is installed at the water outlet of the submersible pump; the test pit is arranged below the ground, the planar size of the test pit is larger than the planar size 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 size of the cover plate is larger than the planar size of the test pit, and a circle of rubber water stop pads in contact with the ground is arranged on the edge bottom surface of the cover plate; the pressurized air bag is laid flat on the bottom surface of the cover plate of the test pit through a support; the air outlet of the air storage tank is connected to the air inlet of the pressurized air bag through an inflation pipe passing through an opening in the cover plate, and the air inlet of the air storage tank is connected to an air compressor; the ballast block is placed on the cover plate of the test pit; the hoisting device is arranged on the ground above the top surface of the test pit; the monitoring platform is arranged on the ground near the test pit, and the monitoring platform is connected to the submersible pump, the opening degree valve, the box internal pressure sensor, the box external pressure sensor, the flow sensor and the air compressor through signal lines respectively; the sealed box is placed on the bottom plate of the test pit, the water level in the test pit is close to the top, and a drainage volume is reserved for the pressurized air bag, so that the test pit is almost filled with water after the cover plate is installed.

2. The performance testing device for a submersible pump for bucket foundation installation according to claim 1, wherein The sealing box adopts a cylinder with a volume not less than 1m 3 The top plate of the sealing box is provided with lifting lugs; the bottom surface of the top plate and the top surface of the bottom plate are respectively provided with annular reinforcing ribs and radial reinforcing ribs; and the inner surface of the side plate is provided with transverse reinforcing ribs and vertical reinforcing ribs.

3. The performance testing device for a submersible pump for bucket foundation installation according to claim 1, wherein The pressurized air bag is composed of a plurality of air bag strips connected in series, the length of each air bag strip is adapted to the length of the cover plate of the test pit, and all the air bag strips are inflated through an air inlet formed on an air bag strip in the middle.

4. A method of testing the performance of a submersible pump for bucket foundation installation, using the performance testing device for a submersible pump for bucket foundation installation according to claim 1, characterized by, The test method includes the following processes: a test preparation process S1 and a test process S2; the test preparation process S1 includes the following steps: S11, install the opening degree valve, the box internal pressure sensor and the box external pressure sensor on the sealed box, install the flow sensor at the water outlet of the submersible pump, then electrically connect the submersible pump, the opening degree valve, the box internal pressure sensor, the box external pressure sensor, the flow sensor and the air compressor to the monitoring platform and debug the connection line, then install the submersible pump in the water pump frame, and then place the water pump frame on the top plate of the sealed box; S12, under the condition that there is no water in the test pit, hoist the sealed box together with the submersible pump to the bottom plate of the test pit. S13, initial water storage, open the opening valve completely before water storage, facilitate the complete discharge of the gas in the sealed tank, fill the tank with water, the water level of this water storage is to reach the submerged pump, keep the opening valve completely open, start the submerged pump to pump water, test whether the submerged pump, the tank pressure sensor, the tank pressure sensor and the flow sensor work normally; S14, secondary water storage, after ensuring that the submerged pump, the tank pressure sensor, the tank pressure sensor and the flow sensor work normally, continue to store water in the test pit to the water level near the cover plate; S15, install the pressure air bag on the bottom surface of the cover plate of the test pit, then cover the cover plate on the top of the test pit, make the rubber water stop pad installed on the bottom surface edge of the cover plate fully contact with the ground to form effective water stop, after the cover plate is installed, the test pit is nearly full of water, then connect the inflation port of the pressure air bag with the gas storage tank and the air compressor in turn through the inflation pipe; S16, stack the 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 in the area range of the cover plate, thus the whole test preparation is completed; The test process S2 includes the following steps: S21, inflate the pressure air bag through the air compressor-gas storage tank, press to the specified test pressure Pt, so that the pressure of the pressure air bag is always Pt, that is, the water depth environment simulation of Pt / 10 is completed; S22, simulate the initial working condition of bucket foundation sinking, start the submersible pump at rated power, and open the opening valve completely, at this time the submersible pump has the maximum pumping flow, reaches the rated pumping capacity of the submersible pump, the sinking resistance of the bucket foundation at this stage is similar to the weight of the bucket foundation, only a small pressure difference between the inside and outside of the box is needed to realize sinking, the pressure difference between the inside and outside of the box tends to 0, the opening valve is kept in a completely open state, after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the box are stable, a set of pumping flow q 100% and the pressure difference between the inside and outside of the box ΔP 100% =P 内100% -P 外100% ; P 内100% is the value monitored by the inside pressure sensor of the opening valve at 100% opening; P 外100% is the value monitored by the outside pressure sensor of the opening valve at 100% opening; S23, the simulation barrel foundation gradually increases with the sinking depth, the sinking resistance increases, need a certain bucket inside and outside pressure difference to realize the sinking of the working condition, keep the submersible pump in the rated power pumping state, the opening of the opening valve is adjusted to 80%, the corresponding submersible pump pumping flow is reduced, the absolute value of the inside and outside pressure difference of the box is increased; after the pumping flow of the submersible pump and the monitoring result of the inside and outside pressure difference of the box are stable, a group of pumping flow q 80% The inside and outside pressure difference of the box ΔP 80% =P 内80% -P 外80% ; P 内80% is the value monitored by the inside pressure sensor of the opening valve at 80% opening; P 外80% is the value monitored by the outside pressure sensor of the opening valve at 80% opening; S24, the simulation barrel foundation gradually increases with the sinking depth, the sinking resistance increases, need a larger bucket inside and outside pressure difference to realize the sinking of the working condition, keep the submersible pump in the rated power of pumping state, the opening of the opening valve is adjusted to 60%, the corresponding submersible pump pumping flow is further reduced, the absolute value of the inside and outside pressure difference of the box is further increased; after the submersible pump pumping flow and the inside and outside pressure difference of the box are stable, a group of submersible pump pumping flow q 60% With the inside and outside pressure difference of the barrel ΔP 60% =P 内60% -P 外60% ; P 内60% The value monitored by the inside pressure sensor of the opening valve at 60% opening; P 外60% The value monitored by the outside pressure sensor of the opening valve at 60% opening; S25, the simulation bucket foundation gradually increases with the sinking depth, the sinking resistance increases, need a larger bucket inside and outside pressure difference to realize the sinking of the working condition, keep the submersible pump in the rated power pumping state, the opening of the opening valve is adjusted to 40%, the corresponding submersible pump pumping flow is further reduced, the absolute value of the box inside and outside pressure difference is further increased; after the submersible pump pumping flow and the box inside and outside pressure difference monitoring result is stable, a group of submersible pump pumping flow q 40% With the box inside and outside pressure difference ΔP 40% =P 内40% -P 外40% ; P 内40% The opening valve is adjusted to 40% opening value; P 外40% The opening valve is adjusted to 40% opening value; S26, the simulation barrel foundation gradually increases with the sinking depth, the sinking resistance increases, need a larger bucket inside and outside pressure difference to realize the sinking of the working condition, keep the submersible pump in the rated power of pumping state, the opening of the opening valve is adjusted to 20%, the corresponding submersible pump pumping flow is further reduced, the absolute value of the inside and outside pressure difference of the box is further increased; after the pumping flow of the submersible pump and the monitoring result of the inside and outside pressure difference of the box are stable, a group of pumping flow q 20% With the inside and outside pressure difference of the barrel ΔP 20% =P 内20% -P 外20% ; P 内20% is the value monitored by the inside pressure sensor of the opening valve at 20% opening; P 外20% is the value monitored by the outside pressure sensor of the opening valve at 20% opening; S27, simulate the difficult working condition of bucket foundation sinking, keep the pumping state of the submersible pump at rated power, set the opening amount of the opening valve to 0%, that is, the opening valve is completely closed, the sum of the self weight of the bucket foundation and the pressure difference between the inside and outside of the bucket is still insufficient to overcome the sinking resistance, the pumping flow of the submersible pump tends to 0, the absolute value of the pressure difference between the inside and outside of the tank tends to the maximum value Pt+Ps, Ps is the difference between the absolute pressure in the tank and the atmospheric pressure caused by the pumping of the submersible pump, that is, Ps is the suction force corresponding to the suction stroke of the submersible pump; after the pumping flow of the submersible pump and the monitoring results of the pressure difference between the inside and outside of the tank are stable, a set of pumping flow q0 of the submersible pump and pressure difference ΔP0=P 内0 -P 外0 ;P 内0 is the value monitored by the inside tank pressure sensor when the opening valve is at 0 opening amount; P 外0 is the value monitored by the outside tank pressure sensor when the opening valve is at 0 opening amount; S28, draw the relationship between the water pumping flow q of the submerged pump and the pressure difference ΔP between the inside and outside of the tank at the same water depth and different opening degrees of the opening valve into a performance curve of the submerged pump under a given water depth environment; S29, adjust the inflation pressure Pt of the pressure air bag, that is, adjust the water depth environment, repeat steps S22 to S28 to obtain the performance curves of the submerged pump under a series of water depth environments.

Images