Underwater throttle valve driver pressure compensation device and method

Abstract

The present invention discloses an underwater throttle valve actuator pressure compensation device and method, relating to the technical field of oil and gas development devices. The device includes a driver body, the top of which is provided with a closable oil filling port and exhaust hole; the bottom of the driver body is provided with a closable inlet check valve and outlet check valve; and an accumulator disposed within the driver body, the top opening of the accumulator communicating with the inner cavity of the driver body, the bottom of the accumulator communicating with the exterior of the driver body via a closable short section; the internal volume of the accumulator is adjustable. The pressure compensation method for the underwater throttle valve actuator pressure compensation device of the present invention has a wide pressure compensation range and can compensate for pressure changes caused by external pressure and temperature changes.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas development devices, and in particular to an underwater throttle valve driver pressure compensation device and method. Background Art

[0002] The subsea throttle valve is a critical component of the subsea tree. Its actuator is subject to external seawater pressure. To prevent deformation and failure due to compression, an accumulator is typically installed to compensate for internal pressure in the actuator, achieving internal and external pressure balance. However, unlike other hydraulic valve actuators, the subsea throttle valve actuator does not share the subsea tree's external compensator to ensure recyclability. Therefore, a compensator must be installed within the subsea throttle valve actuator. Due to the high degree of internal integration and the small footprint of the subsea throttle valve actuator, the compensator's size and compensation capacity are limited. This is especially true as external pressure increases with increasing water depth, making the compensator unable to meet compensation requirements.

[0003] Furthermore, temperature fluctuations cause the volume of the internal gear oil to change with it. Once the compensator has fully compensated for seawater pressure, a temperature drop or rise causes the hydraulic oil volume to change, which in turn reduces or increases the internal pressure. This creates an imbalance between the internal and external pressures of the actuator, leading to deformation and damage. Existing underwater throttle valve compensators are unable to compensate for the pressure changes caused by temperature fluctuations. Summary of the Invention

[0004] The purpose of the present invention is to provide an underwater throttle valve driver pressure compensation device and method to solve the problems existing in the above-mentioned prior art. The pressure compensation range is wide and can compensate for pressure changes caused by external pressure and temperature changes.

[0005] To achieve the above object, the present invention provides the following solutions:

[0006] The present invention provides an underwater throttle valve driver pressure compensation device, comprising a driver body, wherein the top of the driver body is provided with a closable oil filling port and an exhaust hole; the bottom of the driver body is provided with a closable inlet check valve and an outlet check valve; an accumulator, wherein the accumulator is arranged in the driver body, and the upper opening of the accumulator is connected to the inner cavity of the driver body, and the bottom of the accumulator is connected to the outside of the driver body through a closable short section; the internal volume of the accumulator can be changed; and a control system can control the inlet check valve and the outlet check valve according to the pressure value in the accumulator and the pressure values inside and outside the driver body. The opening or closing of the one-way valve and the short joint can also control the opening or closing of the oil filling port and the exhaust hole; the present invention can absorb or discharge the hydraulic oil in the driver body through the accumulator to achieve pressure compensation in the driver when the pressure changes. After the accumulator fully compensates for the seawater pressure, the temperature drops or rises above the set value, causing the volume of the hydraulic oil to change, thereby reducing or increasing the internal pressure. When the internal and external pressures of the driver are unbalanced, the present invention can also discharge the hydraulic oil in the driver body into the seawater, or absorb the seawater into the bottom of the driver body by opening the outlet one-way valve or the inlet one-way valve, to achieve further compensation of the internal and external pressures of the driver.

[0007] Optionally, a driver upper cover is fixedly and sealedly connected to the top of the driver body, and the oil filling port and the exhaust hole are respectively opened on the driver upper cover.

[0008] Optionally, an oil filling port plug is sealed on the oil filling port, and an exhaust hole plug is sealed on the exhaust hole.

[0009] Optionally, the bottom of the driver body is fixedly and sealedly connected to a driver lower cover, the inlet check valve and the outlet check valve are both arranged on the driver lower cover; the short section is arranged on the driver lower cover.

[0010] Optionally, an inlet check valve protective cap is installed at the bottom of the inlet check valve, and an outlet check valve protective cap is installed at the bottom of the outlet check valve.

[0011] Optionally, the short section includes two double-pass short sections, a double-pass short section protective cap is installed at the bottom of the double-pass short section, and filter holes are processed in the circumferential direction of the double-pass short section protective cap to prevent seawater impurities from entering; the top of the double-pass short section is connected to the bottom of the accumulator through a conversion joint.

[0012] Optionally, the accumulator is an airbag structure, a support plate is fixedly provided in the driver body, a mounting hole is provided on the support plate, the top opening of the accumulator is fixedly passed through the mounting hole, and the interior of the accumulator is filled with hydraulic oil in a natural state, with hydraulic oil on the upper part and seawater on the lower part.

[0013] The present invention also provides a method for compensating pressure of an underwater throttle valve driver, comprising the following steps:

[0014] Open the oil filling port and the vent hole, and inject wear-resistant hydraulic oil with a density lower than that of water and insoluble in water from the oil filling port. After filling, close the oil filling port plug and the vent hole plug;

[0015] When the internal pressure of the actuator body is higher than the external pressure and is within the set value, the accumulator expands and discharges part of the seawater from the two-way nipple, while sucking in wear-resistant hydraulic oil from the accumulator opening; when the external pressure of the actuator body is higher than the internal pressure and is within the set value, the accumulator contracts and sucks in part of the seawater from the two-way nipple, and compresses the internal wear-resistant hydraulic oil into the inner cavity of the actuator body;

[0016] When the internal pressure of the driver body exceeds the set value, the accumulators fully expand. While the internal pressure of the driver body remains greater than the external pressure, some hydraulic oil in the driver body is discharged through the outlet check valve to balance the internal and external pressures. When the internal pressure of the driver body falls below the set value, the accumulators fully contract. While the external pressure of the driver body remains higher than the internal pressure, some seawater is drawn into the driver body through the inlet check valve to balance the internal and external pressures. When the driver draws in seawater, oil and water separate, with the seawater existing below the hydraulic oil. When the internal pressure exceeds the external pressure, the seawater is preferentially discharged from the driver. This invention can compensate for pressure changes caused by any situation, ensuring pressure balance between the inside and outside of the driver. The internal components of the driver are made of duplex stainless steel, which will not be corroded by seawater.

[0017] Compared with the prior art, the present invention has achieved the following technical effects:

[0018] The present invention uses an accumulator to absorb or discharge hydraulic oil from the driver body, thereby varying the pressure within the driver body and compensating for various variations in seabed and underwater pressure. When a significant internal and external pressure differential occurs due to temperature fluctuations, in addition to using the accumulator to compensate, a check valve at the bottom of the driver body can be used to discharge hydraulic oil or draw seawater in to achieve pressure changes within the driver body, thereby compensating for temperature-related pressure variations. The dual safeguards of the accumulator and the check valve prevent the risk of internal leakage from damaging driver components and compensate for pressure variations caused by valve stem movement. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 This is a schematic structural diagram of the underwater throttle valve driver pressure compensation device of the present invention;

[0021] Figure 2 This is a schematic diagram of the top structure of the driver body in the present invention;

[0022] Figure 3 Schematic diagram of the structure of the inlet check valve and the outlet check valve in the present invention;

[0023] Figure 4 Schematic diagram of the accumulator structure in the present invention;

[0024] Explanation of the accompanying reference numerals: 1-driver upper cover, 2-driver body, 3-driver lower cover, 4-oil filling port plug, 5-support plate, 6-accumulator, 7-conversion joint, 8-two-way short section, 9-two-way short section protective cap, 10-exhaust hole plug, 11-outlet check valve, 12-outlet check valve protective cap, 13-inlet check valve, 14-inlet check valve protective cap. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide an underwater throttle valve driver pressure compensation device and method to solve the problems existing in the above-mentioned prior art. The pressure compensation range is wide and can compensate for pressure changes caused by external pressure and temperature changes.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] The present invention provides a pressure compensation device for an underwater throttle valve driver. Figure 1 , Attachment Figure 2 , Attachment Figure 3 and attached Figure 4As shown, it includes a driver body 2, a driver upper cover 1 on the top of the driver body 2 is provided with a closable oil filling port and an exhaust hole, the oil filling port is sealed with an oil filling port plug 4, and the exhaust hole is sealed with an exhaust hole plug 10; the driver lower cover 3 at the bottom of the driver body 2 is provided with a closable inlet check valve 13 and an outlet check valve 11, the bottom of the inlet check valve 13 is provided with an inlet check valve protective cap 14, and the bottom of the outlet check valve 11 is provided with an outlet check valve protective cap 12, which can be opened or closed respectively by the command of the control system; an accumulator 6 is fixedly provided in the driver body 2, and the upper opening of the accumulator 6 is in contact with the driver body The inner cavity of the body 2 is connected, and the bottom of the accumulator 6 is connected to the outside of the driver body 2 through a closable short section; the accumulator 6 is an airbag structure, and a support plate 5 is fixedly provided in the driver body 2, and a mounting through hole is provided on the support plate 5. The top opening of the accumulator 6 is fixedly passed through the mounting through hole. In the natural state, the inside of the accumulator 6 is filled with hydraulic oil, the upper part of the accumulator 6 is hydraulic oil, and the lower part is seawater; the control system can control the opening or closing of the inlet check valve 13 and the outlet check valve 11 and the two-way short section 8 according to the pressure value in the accumulator 6 and the internal and external pressure values of the driver body 2, and can also control the opening or closing of the oil filling port and the exhaust hole.

[0029] Further preferably, the pup joint used in the present invention includes two double-way pup joints 8, a double-way pup joint protective cap 9 is installed at the bottom of the double-way pup joint 8, and the double-way pup joint protective cap 9 is processed with filter holes in the circumferential direction to prevent seawater impurities from entering; the top of the double-way pup joint 8 is connected to the bottom of the accumulator 6 through the conversion joint 7.

[0030] The present invention also provides a method for compensating pressure of an underwater throttle valve driver, comprising the following steps:

[0031] When the internal pressure of the driver body 2 exceeds the external pressure, the accumulator 6 expands and discharges some seawater. When the external pressure exceeds the internal pressure, the accumulator 6 contracts, compressing the internal hydraulic oil and entering the inner cavity of the driver body 2, increasing the internal pressure. When the internal pressure is still greater than the external pressure when the accumulator 6 is fully expanded and cannot meet the compensation capacity, some hydraulic oil in the inner cavity of the driver body 2 is discharged through the outlet check valve 11 to balance the internal and external pressures. When the external pressure is still greater than the internal pressure when the accumulator 6 is fully contracted and cannot meet the compensation capacity, some seawater is sucked into the bottom of the inner cavity of the driver body 2 through the inlet check valve 13 to balance the internal and external pressures. The hydraulic oil used in the present invention is a wear-resistant hydraulic oil with a density lower than that of water and is insoluble in water. Therefore, when the driver body 2 draws in seawater, the oil and water separate, and the seawater exists below the hydraulic oil. When the internal pressure exceeds the external pressure, the seawater is preferentially discharged from the driver body 2. This invention can compensate for pressure changes caused by any situation and ensure pressure balance between the inside and outside of the driver body 2.

[0032] Example 1

[0033] In this embodiment, the operating temperature of the actuator body 2 is between -4°C and 66°C, and the water depth is 800m. The accumulator 6 is designed as a 0.7L airbag compensator. The accumulator 6 is naturally filled with wear-resistant hydraulic oil and installed inside the actuator. An outlet check valve 11 is installed below the actuator lower cover 3 to discharge the liquid for compensation, and an inlet check valve 13 is installed to draw in the liquid for compensation. The lower end of the accumulator 6 is connected to the actuator lower cover 3 via a conversion connector 7. Two two-way shorting links 8 are located below the actuator lower cover 3. A two-way shorting link 9 is installed below the two-way shorting link 8. The two-way shorting link 8 has filter holes machined around its circumference to prevent the ingress of seawater impurities. Wear-resistant hydraulic oil with a density lower than that of water is used. The oil inlet plug 4 and the vent plug 10 are opened, and oil is added from the actuator body 2's oil inlet until the oil overflows. The oil inlet plug 4 and the vent plug 10 are then closed. When the heating environment temperature in the pressure and temperature control room is 20°C, the throttle valve opening connected to the oil filling port of the driver body 2 is at the middle position of 50%, and the oil is filled into the inner cavity of the driver body 2 to ensure that the accumulator 6 is fully expanded and filled with hydraulic oil. Then, pressure is applied to the accumulator 6 through the two-way short-circuit 8 below the driver body 2 to discharge 0.375L of lubricating oil inside the driver body 2, and the accumulator 6 is set to the middle position. The pressure and temperature control room is a closed cabinet-like structure that can achieve temperature control. It belongs to the existing technology and will not be described in detail here.

[0034] When the temperature decreases and the internal pressure drops, or when the throttle valve is installed and the external pressure increases, the accumulator 6 contracts, discharging the hydraulic oil in the accumulator 6 into the inner cavity of the actuator body 2, increasing the internal pressure of the actuator. When the liquid in the accumulator 6 is insufficient to compensate for the external pressure, a pressure differential forms between the inside and outside of the actuator body 2, reaching the opening pressure of the inlet check valve 13. Seawater is drawn in to compensate for the external pressure, and the seawater is located below the oil. When the temperature rises and the internal pressure increases, or when the throttle valve is recovered and the external pressure decreases, the accumulator 6 expands, filling the accumulator 6 with hydraulic oil, reducing the internal pressure of the actuator body 2. When the space in the accumulator 6 is insufficient to compensate for the internal pressure, a pressure differential forms between the inside and outside of the actuator body 2, reaching the opening pressure of the outlet check valve 11. The seawater at the bottom of the actuator body 2 is discharged to achieve internal and external pressure balance. The present invention prevents damage to the actuator due to increased internal pressure in the actuator body 2 by providing dual protection through the accumulator 6, the outlet check valve 11, and the inlet check valve 13.

[0035] In the description of the present invention, it should be noted that the terms "center," "top," "bottom," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the method and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A pressure compensation device for an underwater throttle valve actuator, characterized by: The invention comprises a driver body, wherein the top of the driver body is provided with a closable oil filling port and an exhaust hole; the bottom of the driver body is provided with a closable inlet check valve and an outlet check valve; an accumulator, wherein the accumulator is arranged in the driver body, and the upper opening of the accumulator is connected to the inner cavity of the driver body, and the bottom of the accumulator is connected to the outside of the driver body through a closable short section; the internal volume of the accumulator can be changed; the accumulator is an airbag structure, and a support plate is fixedly provided in the driver body, and a mounting through hole is provided on the support plate, and the top opening of the accumulator is fixedly provided in the mounting through hole; When the internal pressure of the driver body is greater than the set value, the accumulators are fully expanded. The internal pressure of the driver body is still greater than the external pressure. Part of the hydraulic oil in the driver body is discharged through the outlet check valve to balance the internal and external pressures. When the internal pressure of the driver body is less than the set value, the accumulators are fully contracted. The external pressure of the driver body is still higher than the internal pressure. Part of the seawater is sucked into the driver body through the inlet check valve to balance the internal and external pressures.

2. The underwater throttle valve actuator pressure compensation device according to claim 1, characterized in that: The top of the driver body is fixedly and sealedly connected with a driver upper cover, and the oil filling port and the exhaust hole are respectively opened on the driver upper cover.

3. The underwater throttle valve actuator pressure compensation device according to claim 2, characterized in that: An oil filling port plug is sealed on the oil filling port, and an exhaust hole plug is sealed on the exhaust hole.

4. The underwater throttle valve actuator pressure compensation device according to claim 1, characterized in that: The bottom of the driver body is fixedly and sealedly connected with a driver lower cover, the inlet check valve and the outlet check valve are both arranged on the driver lower cover; the short section is arranged on the driver lower cover.

5. The underwater throttle valve actuator pressure compensation device according to claim 4, characterized in that: An inlet check valve protection cap is installed at the bottom of the inlet check valve, and an outlet check valve protection cap is installed at the bottom of the outlet check valve.

6. The underwater throttle valve actuator pressure compensation device according to claim 4, characterized in that: The short section includes two double-pass short sections, and a double-pass short section protective cap is installed at the bottom of the double-pass short section; the top of the double-pass short section is connected to the bottom of the accumulator through a conversion joint.

7. A method for compensating underwater throttle valve actuator pressure based on the underwater throttle valve actuator pressure compensation device according to any one of claims 1 to 6, characterized in that: The steps include: Open the oil filling port and the vent hole, and inject wear-resistant hydraulic oil with a density lower than that of water and insoluble in water from the oil filling port. After filling, close the oil filling port plug and the vent hole plug; When the internal pressure of the actuator body is higher than the external pressure and is within the set value, the accumulator expands and discharges part of the seawater from the two-way nipple, while sucking in wear-resistant hydraulic oil from the accumulator opening; when the external pressure of the actuator body is higher than the internal pressure and is within the set value, the accumulator contracts and sucks in part of the seawater from the two-way nipple, and compresses the internal wear-resistant hydraulic oil into the inner cavity of the actuator body; When the internal pressure of the driver body is greater than the set value, the accumulators are fully expanded. The internal pressure of the driver body is still greater than the external pressure. Part of the hydraulic oil in the driver body is discharged through the outlet check valve to balance the internal and external pressures. When the internal pressure of the driver body is less than the set value, the accumulators are fully contracted. The external pressure of the driver body is still higher than the internal pressure. Part of the seawater is sucked into the driver body through the inlet check valve to balance the internal and external pressures.

Images