A device and method for measuring compressibility coefficient of underwater equipment

Abstract

The present invention proposes a device and method for measuring the compressibility coefficient of underwater equipment, and belongs to the technical field of measuring the compressibility coefficient of underwater equipment. In the device for measuring the compressibility coefficient of underwater equipment, an oil bag is arranged in a pressure kettle, the oil inlet end of the oil discharge hydraulic pump is connected to the oil tank via a hydraulic pipeline, and the oil outlet end is connected to the oil bag via a hydraulic pipeline, the oil inlet end of the oil return hydraulic pump is connected to the oil bag via a hydraulic pipeline, and the oil outlet end is connected to the oil tank via a hydraulic pipeline, and a displacement sensor is arranged in the oil tank; a pressure sensor, a water injection port, a drain port and a pressure relief valve are arranged on the pressure kettle, and an assembly part for detachably connecting the underwater equipment is arranged at the bottom of the pressure kettle. The beneficial effects of the present invention: breaking through the limitations of the existing measurement methods, no underwater camera is required, the underwater equipment to be measured is fixed in the pressure kettle without movement, there is no risk of interference and collision, and the measurement operation is simplified.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater equipment compressibility coefficient measurement, and in particular to an underwater equipment compressibility coefficient measurement device and method. Background Art

[0002] Underwater equipment (such as UUVs, profiling buoys, underwater gliders, etc.) mainly completes cruising or hovering operations at different depths by changing their own gravity and buoyancy. However, due to the compressibility of the underwater equipment's own structural parts, the different amounts of compression at different water depths will cause changes in its own buoyancy. Therefore, in order to meet the requirements of underwater equipment's cruising or hovering missions at a predetermined water depth, it is necessary to consider the buoyancy changes caused by the volume compression of the equipment due to water pressure.

[0003] There is currently a method for adjusting a profile drifting buoy in the laboratory. The core idea is to measure the compressibility coefficient of the buoy based on the experimental method, thereby deriving the weight required for the buoy to hover under the target pressure. This method requires tools such as underwater cameras, equipment tooling, scales, and chains of moderate weight. An iron chain is fixed under the buoy, and the pressure cooker is pressurized to increase the buoy's buoyancy and float up, thereby lifting the iron chain. The height of the lifted iron chain is observed through the underwater camera, converted into weight, and the volume compression of the buoy is calculated. The process is relatively cumbersome. There are two limitations to the up and down movement of the buoy during the test: (1) Space for the buoy to move must be reserved, and the equipment itself is relatively large, so the internal space requirements of the pressure cooker are relatively high; (2) There is a risk of interference or collision between the buoy and the inner wall of the pressure cooker or other equipment during movement, affecting the measurement accuracy or causing damage to the buoy. Summary of the invention

[0004] The purpose of the present invention is to provide a device and method for measuring the compressibility coefficient of underwater equipment, which breaks through the limitations of existing measurement methods, does not require an underwater camera, and the underwater equipment to be measured is fixed in a pressure vessel without movement, without the risk of interference and collision, thereby simplifying the measurement operation.

[0005] The invention provides a device for measuring the compressibility coefficient of underwater equipment, comprising a pressure kettle, an oil discharge hydraulic pump, an oil return hydraulic pump and an oil tank, wherein an oil bag made of a flexible material is arranged in the pressure kettle, an oil inlet end of the oil discharge hydraulic pump is connected to the oil tank via a hydraulic pipeline, an oil outlet end of the oil discharge hydraulic pump is connected to the oil bag via a hydraulic pipeline, an oil inlet end of the oil return hydraulic pump is connected to the oil bag via a hydraulic pipeline, an oil outlet end of the oil return hydraulic pump is connected to the oil tank via a hydraulic pipeline, a displacement sensor is arranged in the oil tank; a pressure sensor is arranged on the pressure kettle, and a detection part of the pressure sensor is connected to the pressure kettle; a water injection port is arranged on the pressure kettle, and the water injection port is connected to the pressure kettle via a water injection pipeline; a water discharge port is arranged on the pressure kettle, and the water discharge port is connected to the pressure kettle via a water discharge pipeline; a pressure relief valve is arranged on the pressure kettle, and the pressure relief valve is connected to the top of the pressure kettle via an exhaust pipeline; an assembly part for detachably connecting underwater equipment is arranged at the bottom of the pressure kettle.

[0006] Preferably, the pressure autoclave comprises a cylinder and a cover, the top of the cylinder is open, the cover can be detachably assembled at the opening, and the end of the exhaust pipeline is located at the lower surface of the cover.

[0007] Preferably, a groove is formed on the lower surface of the cover body, and the end of the exhaust pipe is located at the deepest part of the groove.

[0008] Preferably, the groove is configured as a conical groove, and the end of the exhaust pipe is located at the center of the conical groove.

[0009] Preferably, the assembly portion is configured as a support seat, the bottom of the support seat is fixedly connected to the bottom of the pressure vessel, and the top of the support seat is provided with bolts that can be bolted to the underwater equipment.

[0010] Preferably, the oil bag is made of fluororubber material.

[0011] The present invention also provides a method for measuring the compressibility coefficient of underwater equipment, which uses the above-mentioned device for measuring the compressibility coefficient of underwater equipment, and comprises the following steps:

[0012] Step A, placing the underwater equipment in the autoclave, and then connecting the underwater equipment to the assembly part in the autoclave, and then performing steps A1 to A3.

[0013] Step A1, fill the autoclave with water through the water injection port, discharge the gas in the autoclave through the pressure relief valve, and close the water injection port after the autoclave is filled with water;

[0014] Step A2, the oil discharge hydraulic pump injects hydraulic oil into the oil bag to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor, the height change of the hydraulic oil in the oil tank is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil;

[0015] Step A3: During the pressure increase process in the autoclave, there is a balance equation:

[0016] V0(1-α 样 (t)P)+(V 釜 -V0)(1-α 水 (t)P)+ΔV2(P)P=ΔV(1-α Δ (t)P)+ΔV1(P)P (Formula 1.1)

[0017] Let E(P) = ΔV1(P) - ΔV2(P), equation 1.1 can be rewritten as

[0018] V0(1-α 样 (t)P)+(V 釜 -V0)(1-α 水 (t)P)=ΔV(1-α Δ (t)P)+E(P)P (Formula 1.2)

[0019] Step B: There is no underwater equipment in the autoclave, and steps B1 to B3 are implemented.

[0020] Step B1, fill the autoclave with water through the water injection port, discharge the gas in the autoclave through the pressure relief valve, and close the water injection port after the autoclave is filled with water;

[0021] Step B2, the oil discharge hydraulic pump injects hydraulic oil into the oil bag to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor, the height change of the hydraulic oil in the oil tank is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil;

[0022] Step B3: During the pressure increase process in the autoclave, there is a balance equation:

[0023] (V 釜 -V0)(1-α 水 (t)P)+ΔV2(P)P=ΔV(1-α Δ (t)P)+ΔV1(P)P (Formula 1.3)

[0024] Let E(P) = ΔV1(P) - ΔV2(P), equation 1.3 can be rewritten as

[0025] E(P)=(V 釜 -V0)(1-α 水 (t)P)-ΔV(1-α Δ (t)P) (Formula 1.4)

[0026] From equation 1.2 and equation 1.4, we get α 样 (t);

[0027] in,

[0028] V0 is the volume of the underwater equipment under normal pressure;

[0029] α 样 (t) is the compressibility factor of the underwater equipment;

[0030] P is the pressure in the autoclave;

[0031] V 釜 is the volume of the autoclave at normal pressure;

[0032] α 水 (t) is the compressibility coefficient of water;

[0033] ΔV2(P) is the compression of the inherent facilities in the autoclave under pressure P;

[0034] ΔV is the volume of injected hydraulic oil at normal pressure;

[0035] α Δ (t) is the compressibility coefficient of hydraulic oil;

[0036] ΔV1(P) is the volume increment of the autoclave under pressure P.

[0037] Compared with the prior art, the underwater equipment compressibility coefficient measuring device and method of the present invention has the following characteristics and advantages:

[0038] The underwater equipment compressibility coefficient measuring device of the present invention does not need to be equipped with an underwater camera, has a simple structure, and has a low cost investment. The underwater equipment to be measured is fixed on the assembly part in the pressure autoclave, and the underwater equipment does not move in the pressure autoclave, and there is no risk of interference and collision. The underwater equipment compressibility coefficient measuring method of the present invention, using the underwater equipment compressibility coefficient measuring device of the present invention, can measure the compressibility coefficient of the underwater equipment under a high-pressure environment in a laboratory environment, the measurement operation is simple, the measurement data is accurate, and it provides a data basis for the depth cruise and depth hovering of the underwater unmanned motion platform, and has a high value of promotion and application.

[0039] After reading the specific embodiments of the present invention in conjunction with the accompanying drawings, the characteristics and advantages of the present invention will become more clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 It is a cross-sectional view of the compressibility coefficient measuring device of underwater equipment in the embodiment. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0043] In the description of the present invention, it should be noted that the terms "inside", "outside", "upper", "lower", "front", "back", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0044] like Figure 1 As shown, this embodiment provides a device for measuring the compressibility coefficient of underwater equipment, including a pressure vessel, a pressure sensor 1, an oil tank 2, an oil return hydraulic pump 3, an oil discharge hydraulic pump 4, an oil bag 5 and a pressure relief valve 6, etc.

[0045] The pressure autoclave comprises a cylinder 8 and a cover 7. The top of the cylinder 8 is open, and the cover 7 can be detachably assembled at the opening of the cylinder 8.

[0046] A groove is provided on the lower surface of the cover 7, and the shape of the groove is preferably designed as a conical groove. The pressure relief valve 6 is arranged on the cover 7, and the pressure relief valve 6 is connected to the top of the autoclave through the exhaust pipe 13, and the end of the exhaust pipe 13 is located at the center (deepest) of the conical groove. When water is injected into the autoclave through the water injection port 10, the air above the water surface in the autoclave can be smoothly discharged through the exhaust pipe 13 and the pressure relief valve 6 along the conical groove, avoiding the retention of air in the autoclave, so that the autoclave is filled with water.

[0047] A pressure sensor 1 is provided on the side wall of the cylinder 8 of the autoclave, and a detection part of the pressure sensor 1 is connected to the inside of the autoclave. The pressure sensor 1 detects the pressure P in the autoclave in real time.

[0048] A water injection port 10 is provided on the side wall of the cylinder 8 of the autoclave, and the water injection port 10 is connected to the autoclave through a water injection pipeline. Water is injected into the autoclave through the water injection port 10.

[0049] A drain port 11 is provided on the side wall of the cylinder 8 of the autoclave, and the drain port 11 is connected to the autoclave through a drain pipe. After the measurement is completed, the drain port 11 is opened to drain the water in the autoclave.

[0050] An oil bladder 5 made of a flexible material is arranged in the autoclave. In this embodiment, the material of the oil bladder 5 is preferably fluororubber.

[0051] The oil tank 2 is filled with hydraulic oil, the oil inlet of the oil discharge hydraulic pump 4 is connected to the oil tank 2 via a hydraulic pipeline, the oil outlet of the oil discharge hydraulic pump 4 is connected to the oil bladder 5 via a hydraulic pipeline, the oil inlet of the oil return hydraulic pump 3 is connected to the oil bladder 5 via a hydraulic pipeline, and the oil outlet of the oil return hydraulic pump 3 is connected to the oil tank 2 via a hydraulic pipeline. A displacement sensor is provided in the oil tank 2. The displacement sensor measures the height change of the hydraulic oil in the oil tank 2 and can be converted to obtain the normal pressure volume ΔV of the hydraulic oil injected into the oil bladder 5.

[0052] The oil discharge hydraulic pump 4 can inject the hydraulic oil in the oil tank 2 into the oil bag 5 , and the oil return hydraulic pump 3 can discharge the hydraulic oil in the oil bag 5 into the oil tank 2 .

[0053] Hydraulic oil is injected into the oil bag 5, and the oil bag 5 expands to increase the pressure in the autoclave. The pressure in the autoclave is changed by changing the volume of the oil bag 5.

[0054] The bottom of the autoclave cylinder 8 is provided with an assembly part, which is used for detachably connecting the underwater device 9 to be tested. In this embodiment, the assembly part is provided as a support seat 12, the bottom of the support seat 12 is fixedly connected to the bottom of the autoclave cylinder 8, and the top of the support seat 12 is provided with bolts, through which the underwater device 9 to be tested is connected. In this way, during the measurement process, the underwater device 9 is prevented from drifting due to the pressure change in the autoclave, and there is no risk of interference and collision.

[0055] This embodiment also provides a method for measuring the compressibility coefficient of underwater equipment, which uses the above-mentioned device for measuring the compressibility coefficient of underwater equipment and includes the following steps.

[0056] Step A, placing the underwater equipment 9 in the cylinder 8 of the autoclave, connecting the underwater equipment 9 to the assembly part in the autoclave and closing the cover 7 on the cylinder 8, and then implementing steps A1 to A3:

[0057] Step A1, fill the autoclave with water through the water injection port 10, discharge the gas in the autoclave through the pressure relief valve 6, close the water injection port 10 after the autoclave is filled with water, and set the safety pressure of the pressure relief valve 6;

[0058] Step A2, the oil discharge hydraulic pump 4 injects hydraulic oil into the oil bag 5 to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor 1, the height change of the hydraulic oil in the oil tank 2 is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil;

[0059] Step A3: During the pressure increase process in the autoclave, there is a balance equation:

[0060] V0(1-α 样 (t)P)+(V 釜 -V0)(1-α 水 (t)P)+ΔV2(P)P=ΔV(1-αΔ (t)P)+ΔV1(P)P (Formula 1.1)

[0061] Let E(P) = ΔV1(P) - ΔV2(P), equation 1.1 can be rewritten as

[0062] V0(1-α 样 (t)P)+(V 釜 -V0)(1-α 水 (t)P)=ΔV(1-α Δ (t)P)+E(P)P (Formula 1.2)

[0063] Step B: There is no underwater equipment 9 in the autoclave, the cover 7 is closed on the cylinder 8, and then steps B1 to B3 are implemented:

[0064] Step B1, fill the autoclave with water through the water injection port 10, discharge the gas in the autoclave through the pressure relief valve 6, close the water injection port 10 after the autoclave is filled with water, and set the safety pressure of the pressure relief valve 6;

[0065] Step B2, the oil discharge hydraulic pump 4 injects hydraulic oil into the oil bag 5 to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor 1, the height change of the hydraulic oil in the oil tank 2 is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil;

[0066] Step B3: During the pressure increase process in the autoclave, there is a balance equation:

[0067] (V 釜 -V0)(1-α 水 (t)P)+ΔV2(P)P=ΔV(1-α Δ (t)P)+ΔV1(P)P (Formula 1.3)

[0068] Let E(P) = ΔV1(P) - ΔV2(P), equation 1.3 can be rewritten as

[0069] E(P)=(V 釜 -V0)(1-α 水 (t)P)-ΔV(1-α Δ (t)P) (Formula 1.4)

[0070] From equation 1.2 and equation 1.4, we get α 样 (t);

[0071] in,

[0072] V0 is the volume of the underwater equipment under normal pressure;

[0073] α 样 (t) is the compressibility factor of the underwater equipment;

[0074] P is the pressure in the autoclave;

[0075] V 釜 is the volume of the autoclave at normal pressure;

[0076] α 水 (t) is the compressibility coefficient of water;

[0077] ΔV2(P) is the compression of the inherent facilities in the autoclave under pressure P;

[0078] ΔV is the volume of injected hydraulic oil at normal pressure;

[0079] α Δ (t) is the compressibility coefficient of hydraulic oil;

[0080] ΔV1(P) is the volume increment of the autoclave under pressure P.

[0081] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A compressibility coefficient measuring device for underwater equipment, comprising a pressure vessel, an oil discharge hydraulic pump, an oil return hydraulic pump and an oil tank, characterized in that: An oil bag made of flexible material is arranged in the pressure autoclave, the oil inlet end of the oil discharge hydraulic pump is connected to the oil tank through a hydraulic pipeline, the oil outlet end of the oil discharge hydraulic pump is connected to the oil bag through a hydraulic pipeline, the oil inlet end of the oil return hydraulic pump is connected to the oil bag through a hydraulic pipeline, the oil outlet end of the oil return hydraulic pump is connected to the oil tank through a hydraulic pipeline, and a displacement sensor is arranged in the oil tank; The pressure autoclave is provided with a pressure sensor, and the detection part of the pressure sensor is connected with the inside of the pressure autoclave; The pressure vessel is provided with a water injection port, which is connected to the pressure vessel through a water injection pipeline; The pressure vessel is provided with a drain port, which is connected to the pressure vessel through a drain pipeline; The pressure autoclave is provided with a pressure relief valve, which is connected to the top of the pressure autoclave through an exhaust pipe; The bottom of the pressure vessel is provided with an assembly part for detachably connecting underwater equipment.

2. The underwater equipment compressibility coefficient measuring device according to claim 1, characterized in that: The pressure autoclave comprises a cylinder and a cover. The top of the cylinder is open, and the cover can be detachably assembled at the opening. The end of the exhaust pipeline is located at the lower surface of the cover.

3. The underwater equipment compressibility coefficient measuring device according to claim 2, characterized in that: A groove is formed on the lower surface of the cover body, and the end of the exhaust pipe is located at the deepest part of the groove.

4. The underwater equipment compressibility coefficient measuring device according to claim 3, characterized in that: The groove is configured as a tapered groove, and the end of the exhaust pipe is located at the center of the tapered groove.

5. The underwater equipment compressibility coefficient measuring device according to claim 1, characterized in that: The assembly portion is configured as a support seat, the bottom of the support seat is fixedly connected to the bottom of the pressure vessel, and the top of the support seat is provided with bolts that can be bolted to the underwater equipment.

6. The compressibility coefficient measuring device for underwater equipment according to claim 1, characterized in that: The oil bag is made of fluororubber material.

7. A method for measuring the compressibility coefficient of underwater equipment, using the underwater equipment compressibility coefficient measuring device according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step A, placing the underwater equipment in the autoclave, and then connecting the underwater equipment to the assembly part in the autoclave, and then performing steps A1 to A3. Step A1, fill the autoclave with water through the water injection port, discharge the gas in the autoclave through the pressure relief valve, and close the water injection port after the autoclave is filled with water; Step A2, the oil discharge hydraulic pump injects hydraulic oil into the oil bag to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor, the height change of the hydraulic oil in the oil tank is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil; Step A3: During the pressure increase process in the autoclave, there is a balance equation: V0(1-a 样 (t)P)+(V 釜 -V0)(1-a 水 (t)P)+ΔV2(P)P=ΔV(1-α Δ (t)P)+ΔV1(P)P (equation 1.1) Let E(P) = ΔV1(P) - ΔV2(P), equation 1.1 can be rewritten as V0(1-α 样 (t)P)+(V 釜 -V0)(1-α 水 (t)P)=ΔV(1-α Δ (t)P)+E(P)P (Equation 1.2) Step B: There is no underwater equipment in the autoclave, and steps B1 to B3 are implemented. Step B1, fill the autoclave with water through the water injection port, discharge the gas in the autoclave through the pressure relief valve, and close the water injection port after the autoclave is filled with water; Step B2, the oil discharge hydraulic pump injects hydraulic oil into the oil bag to increase the pressure in the autoclave, the pressure P in the autoclave is measured by the pressure sensor, the height change of the hydraulic oil in the oil tank is measured by the displacement sensor and converted to obtain the normal pressure volume ΔV of the injected hydraulic oil; Step B3: During the pressure increase process in the autoclave, there is a balance equation: (V 釜 -V0)(1-a 水 (t)P)+ΔV2(P)P=ΔV(1-α Δ (t)P)+ΔV1(P)P (equation 1.3) Let E(P) = ΔV1(P) - ΔV2(P), equation 1.3 can be rewritten as E(P) = (V 釜 - V0)(1 - α 水 (t)P) - ΔV(1 - α Δ (t)P) (Equation 1.4) From equation 1.2 and equation 1.4, we get α 样 (t); in, V0 is the volume of the underwater equipment under normal pressure; α 样 (t) is the compressibility factor of the underwater equipment; P is the pressure in the autoclave; V 釜 is the volume of the autoclave at normal pressure; α 水 (t) is the compressibility coefficient of water; ΔV2(P) is the compression of the inherent facilities in the autoclave under pressure P; ΔV is the volume of injected hydraulic oil at normal pressure; α Δ (t) is the compressibility coefficient of hydraulic oil; ΔV1(P) is the volume increment of the autoclave under pressure P.

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