High-pressure water injection device of liquefied petroleum gas storage tank

Abstract

The utility model relates to the technical field of high-pressure water injection leakage stoppage of a full-pressure liquefied petroleum gas storage tank, and discloses a high-pressure water injection device of a liquefied petroleum gas storage tank, which comprises a storage tank, a first variable-frequency water injection pump and a second variable-frequency water injection pump, the water injection main pipe is sequentially provided with a manual control valve and an electric control valve. The pressure of the device is adjusted in real time through the first variable-frequency water injection pump and the second variable-frequency water injection pump, the pressure of the water injection device is prevented from being too large or too small, a storage tank and a pipeline are protected, and stable operation of the device is ensured. The manual control valve and the electric control valve which are installed on the water injection main pipe can effectively prevent liquefied petroleum gas from flowing back into the water injection main pipe in emergency, and multi-level safety guarantee is provided.

Description

Technical Field

[0001] The utility model relates to the technical field of high-pressure water injection and leakage plugging for fully pressurized liquefied petroleum gas storage tanks, and particularly relates to a high-pressure water injection device applicable to liquefied petroleum gas storage tanks. Background Technique

[0002] A liquefied petroleum gas (LPG) storage and distribution station is a facility for storing and distributing liquefied petroleum gas. According to research, most existing LPG storage and distribution station storage tanks are not equipped with glue injection or high-pressure water injection devices. A small number of LPG storage and distribution stations equipped with high-pressure water injection devices are newly built stations or are retrofitted later, and the glue injection devices are also purchased later. Moreover, there are certain limitations in using glue injection to plug leaks. It has relatively high requirements for the emergency handling ability of operators, and there is a relatively high risk of plugging leaks under pressure in the storage tank area. Especially when the leakage volume is large, personnel cannot approach the leakage source, and the glue injection device cannot be used. Therefore, installing a high-pressure water injection device is a relatively safe and reliable method for plugging leaks.

[0003] In the existing related technologies, there are mainly three high-pressure water injection technologies for liquefied petroleum gas storage tanks. The first is to inject water through a reserved water injection port. The water injection pipeline is connected to the water injection port by an independent pipeline. A bottom-of-tank root valve, a check valve, and a water injection operation valve (which can be remotely controlled) are set on the pipeline. Among them, the bottom-of-tank root valve is normally open, and the water injection operation valve is normally closed. The advantage of this solution is that the water injection system is not affected by the process system, and the injected fire water can directly reach the inside of the tank. Moreover, the pipe size and pressure rating of the water injection pipeline can be designed separately, and the water injection volume can be guaranteed. However, there is a risk of overpressure during water injection, which may cause damage to the storage tank.

[0004] The second is to inject water through the process medium pipeline. The water injection pipeline is not directly connected to the storage tank, but realizes the injection of fire water through the process medium pipeline connected to the storage tank. A check valve and a water injection operation valve are set before the pipeline is connected to the process pipeline. The advantage of this solution is that it reduces the openings on the tank wall of the storage tank and reduces potential leakage sources. The disadvantage of this solution is that the water injection system will be interfered by the state of the process medium pipeline. For example, if the emergency cut-off valve on the process medium pipeline leaks or fails internally, resulting in the emergency cut-off valve not closing tightly, at this time, the fire water will flow into the downstream of the pipeline, polluting the entire material. The emergency cut-off valve of the storage tank is generally interlocked with the liquid level of the storage tank, rather than with the leakage of the bottom flange of the tank. Therefore, as long as the liquid level of the storage tank does not alarm, the emergency cut-off valve will not automatically cut off. If the bottom flange of the tank leaks, unless a gas detection alarm or personnel inspection discovers it, and the emergency cut-off valve is manually closed and then the water injection operation valve is opened, can effective water injection be achieved. This series of operations is very likely to lead to carelessness and complications, and there are great practical risks. Moreover, the connection point of the water injection line must be selected between the emergency cut-off valve and the bottom-of-tank root valve, and cannot be directly connected downstream of the emergency cut-off valve. Otherwise, once the emergency cut-off valve is closed, the water injection system will fail.

[0005] The third method is to inject water through the sewage outlet. The water injection pipeline realizes water injection by accessing the sewage pipeline at the bottom of the storage tank. The advantage of this solution is that it avoids opening holes in the tank wall and is not affected by the state of the process medium pipeline, seemingly relatively perfect. However, the disadvantage of this solution is that when using the sewage pipeline for water injection, the pipeline size of the general sewage pipeline is not too large, and the conventional pipe diameter is about DN50, and the water injection volume may not meet the requirements.

[0006] There are no clear technical regulations on the design of high-pressure water injection devices in the relevant national standards and specifications issued. Each local gas enterprise or design institute only adds the above-mentioned storage tank leakage plugging devices based on their own understanding, without a unified technical standard, and it is impossible to verify its effectiveness.

[0007] Therefore, how to solve the high-pressure water injection of liquefied petroleum gas storage tanks conveniently, effectively, comprehensively and economically is a technical problem that needs to be solved at present. Summary of the Invention

[0008] In view of the above technical problems, the utility model provides a high-pressure water injection device for a liquefied petroleum gas storage tank, which realizes the stability of the system pressure through a variable-frequency water injection pump, prevents the pressure of the water injection system from being too large or too small, and prevents liquefied petroleum gas from flowing back into the water injection main pipe in case of emergencies through the electric control valve and manual control valve installed on the water injection main pipe.

[0009] The above technical purpose of the utility model is achieved through the following technical solutions: A high-pressure water injection device for a liquefied petroleum gas storage tank includes a storage tank, a first variable-frequency water injection pump, and a second variable-frequency water injection pump. The storage tank is divided into two paths through a water injection main pipe and is respectively connected to the first variable-frequency water injection pump and the second variable-frequency water injection pump. The water injection main pipe is sequentially provided with a manual control valve and an electric control valve.

[0010] By adopting the above technical solutions, the real-time adjustment of the device pressure is realized by using the first variable-frequency water injection pump and the second variable-frequency water injection pump, avoiding the pressure of the water injection device from being too large or too small, thereby protecting the storage tank and pipeline and ensuring the stable operation of the device. The manual control valve and electric control valve installed on the water injection main pipe can effectively prevent liquefied petroleum gas from flowing back into the water injection main pipe in case of emergencies.

[0011] Furthermore, a relief valve is arranged on the water injection main pipe, and a pressure gauge is installed between the relief valve and the storage tank.

[0012] By adopting the above technical solution, a relief valve is provided. When the device pressure exceeds the set value, the relief valve will automatically release the excess pressure, avoiding secondary damage to the storage tank caused by excessive device pressure. The pressure gauge detects the device pressure in real time, enabling the operator to understand the pressure state of the water injection device at any time. Measures can be taken in advance when the pressure approaches the safety critical value to avoid overpressure accidents caused by excessive device pressure. The relief valve can be automatically triggered according to the preset pressure limit value. When the device pressure exceeds the set value, the relief valve can promptly release the excess pressure to ensure that the device operates within the safe pressure range.

[0013] Furthermore, a pressure transmitter is provided between the first variable-frequency water injection pump and the second variable-frequency water injection pump.

[0014] By adopting the above technical solution, the pressure transmitter provides high-precision pressure monitoring, enabling the device to accurately display the pressure state between the variable-frequency water injection pumps, ensuring that the device operates within the optimal pressure range. It can also feedback the pressure data to the control system of the variable-frequency water injection pump in real time to automatically adjust the operating speed and output pressure of the water injection pump and maintain the stability of the system pressure.

[0015] Furthermore, the first variable-frequency water injection pump is connected to the water injection pool through the first water injection branch pipe, and the second variable-frequency water injection pump is connected to the water injection pool through the second water injection branch pipe. A swirl preventer is installed on both the first water injection branch pipe and the second water injection branch pipe.

[0016] By adopting the above technical solution, the swirl preventer can effectively prevent the generation of swirl phenomena due to the high-speed flowing water during the water injection process, reduce the eddy current and pressure fluctuations in the pipeline, and ensure the stability and uniformity of the water flow. By eliminating the swirl, the water injection process is more stable and uniform, enabling better control of the water injection volume and speed, and improving the water injection effect and efficiency.

[0017] Furthermore, the storage tank includes a first storage tank and a second storage tank. The first storage tank is connected to the water injection main pipe through the third water injection branch pipe, and the second storage tank is connected to the water injection main pipe through the fourth water injection branch pipe.

[0018] By adopting the above technical solution, the independent connection between multiple storage tanks improves the redundancy of the device. When a problem occurs in one storage tank or its water injection branch pipe, it will not affect the normal operation of other storage tanks. The design of multiple storage tanks and independent water injection branch pipes enables the system to better manage and distribute the water injection pressure, avoiding excessive or too low pressure in a single pipeline, and improving the pressure control accuracy and the overall performance of the device.

[0019] Furthermore, the third water injection branch pipe is successively installed with a first root valve, a first check valve, a first electric control valve, and a first manual control valve; the fourth water injection branch pipe is successively installed with a second root valve, a second check valve, a second electric control valve, and a second manual control valve.

[0020] By adopting the above technical solution, installing multiple valves (root valve, check valve, electric control valve, manual control valve) on the water injection branch pipe provides multi-level safety protection. The valves can be closed separately under different circumstances to prevent the leakage or backflow of liquefied petroleum gas. The check valve can effectively prevent the backflow of liquefied petroleum gas or water in the pipeline, ensuring that the liquid can only flow in one direction. By setting the electric control valve and the manual control valve, the combination of remote control and on-site control is realized, and the operation mode can be selected according to specific conditions. The root valve and the manual control valve are set to facilitate isolating specific parts of the water injection branch pipe during maintenance and repair, reducing the impact on other parts of the device.

[0021] Further setting: The pipeline between the second root valve and the second check valve of the fourth water injection branch pipe is connected to a sewage discharge branch pipe, and a third manual control valve is installed on the sewage discharge branch pipe.

[0022] By adopting the above technical solution, by adding a sewage discharge branch pipe and its control valves, when it is impossible to increase the water injection port of the existing storage tank, the water injection operation can be realized by connecting the water injection branch pipe through the opening of the drainage branch pipe.

[0023] Further setting: A low-point drain port is installed on the water injection main pipe to empty all pipelines and storage tanks through the low-point drain port.

[0024] By adopting the above technical solution, the setting of the low-point drain port enables all pipelines and storage tanks in the water injection system to be quickly emptied when needed, facilitating maintenance, repair or emergency treatment. Regularly using the low-point drain port to drain the accumulated water in the pipeline can prevent the long-term retention of accumulated water in the pipeline, reducing the risks of corrosion and scaling. In case of emergency, the water in the system can be quickly emptied through the low-point drain port, reducing the pressure in the storage tank and preventing the rupture of the storage tank or other safety accidents caused by excessive pressure.

[0025] Further setting: A water hammer absorber is installed on the water injection main pipe to eliminate water hammer phenomenon.

[0026] By adopting the above technical solution, the water hammer absorber can effectively absorb and relieve the water hammer impact caused by suddenly closing the valve or starting and stopping the pump, preventing the pressure fluctuation caused by the rapid change of the water flow in the pipeline.

[0027] To sum up, the utility model has the following beneficial effects:

[0028] 1. The utility model realizes the real-time adjustment of the device pressure by adopting the first variable-frequency water injection pump and the second variable-frequency water injection pump, avoiding excessive or too low pressure of the water injection device, thereby protecting the storage tank and pipeline and ensuring the stable operation of the device. The manual control valve and the electric control valve installed on the main water injection pipe can effectively prevent the reverse flow of liquefied petroleum gas into the main water injection pipe in case of emergencies, providing multi-level safety protection. The pressure gauge detects the device pressure in real time, enabling the operator to understand the pressure state of the water injection device at any time, and can take measures in advance when the pressure approaches the safety critical value to avoid overpressure accidents caused by too high device pressure.

[0029] 2. The utility model is provided with a swirl preventer, which can effectively prevent the swirl phenomenon generated by the high-speed flowing water during the water injection process, ensuring the stability and uniformity of the water flow, thereby improving the water injection effect and efficiency. The pressure transmitter provides high-precision pressure monitoring and automatic adjustment capabilities, ensuring that the device operates within the optimal pressure range, and improving the stability and reliability of the system. The design of multiple storage tanks and independent water injection branch pipes enables the system to better manage and distribute the water injection pressure, improving the accuracy of pressure control and the overall performance of the device.

[0030] 3. The utility model is provided with a low-point drain port, which enables all pipelines and storage tanks in the water injection system to be quickly emptied when needed, facilitating maintenance, repair or emergency treatment, and reducing the risk of corrosion and scaling. The water hammer absorber can effectively absorb and relieve the water hammer impact caused by suddenly closing the valve or starting and stopping the pump, preventing the pressure fluctuation caused by the rapid change of the water flow in the pipeline, protecting the pipeline and equipment, and ensuring the smoothness and continuity of the system operation. The setting of multiple valves provides multi-level safety protection, and the valves can be closed separately in different situations to prevent the leakage or backflow of liquefied petroleum gas, facilitating maintenance and repair. Description of the Drawings

[0031] Figure 1 is a schematic structural diagram of a high-pressure water injection device for a liquefied petroleum gas storage tank in a preferred embodiment;

[0032] Figure 2 is a schematic structural diagram of the storage tank.

[0033] Reference numerals: 1, storage tank; 1-1, first storage tank; 1-2, second storage tank;

[0034] 2, first variable-frequency water injection pump; 2-1, manual control valve; 2-2, electric control valve; 2-3, relief valve; 2-4, pressure gauge; 2-5, pressure transmitter;

[0035] 3, second variable-frequency water injection pump;

[0036] 4, main water injection pipe; 4-1, low-point drain port; 4-2, water hammer absorber;

[0037] 5, water injection pool; 6, first water injection branch pipe; 7, second water injection branch pipe; 8, swirl preventer;

[0038] 9, third water injection branch pipe; 9-1, first root valve; 9-2, first check valve; 9-3, first electric control valve; 9-4, first manual control valve;

[0039] 10, fourth water injection branch pipe; 10-1, second root valve; 10-2, second check valve; 10-3, second electric control valve; 10-4, second manual control valve;

[0040] 11, sewage discharge branch pipe; 11-1, third manual control valve. Detailed implementation mode

[0041] The preferred embodiments of the present utility model will be described in detail below with reference to the accompanying drawings.

[0042] As Figure 1-2 shown, a high-pressure water injection device for a liquefied petroleum gas storage tank in a preferred embodiment includes a storage tank 1, a first variable-frequency water injection pump 2, and a second variable-frequency water injection pump 3. The storage tank 1 is divided into two paths through a water injection main pipe 4 and is respectively connected to the first variable-frequency water injection pump 2 and the second variable-frequency water injection pump 3. A manual control valve 2-1 and an electric control valve 2-2 are sequentially arranged on the water injection main pipe 4. A relief valve 2-3 is arranged on the water injection main pipe 4, and a pressure gauge 2-4 is installed between the relief valve 2-3 and the storage tank 1. A pressure transmitter 2-5 is arranged between the first variable-frequency water injection pump 2 and the second variable-frequency water injection pump 3.

[0043] The first variable-frequency water injection pump 2 is connected to the water injection pool 5 through the first water injection branch pipe 6, and the second variable-frequency water injection pump 3 is connected to the water injection pool 5 through the second water injection branch pipe 7. A swirl preventer 8 is installed on both the first water injection branch pipe 6 and the second water injection branch pipe 7.

[0044] The storage tank 1 includes a first storage tank 1-1 and a second storage tank 1-2. The first storage tank 1-1 is connected to the water injection main pipe 4 through the third water injection branch pipe 9, and the second storage tank 1-2 is connected to the water injection main pipe 4 through the fourth water injection branch pipe 10. A first root valve 9-1, a first check valve 9-2, a first electric control valve 9-3, and a first manual control valve 9-4 are sequentially installed on the third water injection branch pipe 9; a second root valve 10-1, a second check valve 10-2, a second electric control valve 10-3, and a second manual control valve 10-4 are sequentially installed on the fourth water injection branch pipe 10. The pipe between the second root valve 10-1 and the second check valve 10-2 of the fourth water injection branch pipe 10 is connected to the sewage discharge branch pipe 11, and a third manual control valve 11-1 is installed on the sewage discharge branch pipe 11.

[0045] A low-point drain port 4-1 is installed on the water injection main pipe 4 to empty all pipes and the storage tank 1 through the low-point drain port 4-1. A water hammer absorber 4-2 is installed on the water injection main pipe 4 to eliminate the water hammer phenomenon.

[0046] In the initial state of the system, liquefied petroleum gas is stored in storage tank 1. The first storage tank 1-1 and the second storage tank 1-2 are connected to the water injection main pipe 4 through the third water injection branch pipe 9 and the fourth water injection branch pipe 10. The first variable-frequency water injection pump 2 and the second variable-frequency water injection pump 3 are in the standby state, and there is sufficient water in the water injection pool 5. Start the first variable-frequency water injection pump 2 and the second variable-frequency water injection pump 3, and water enters the variable-frequency water injection pumps from the water injection pool 5 through the first water injection branch pipe 6 and the second water injection branch pipe 7 respectively. After the water injection pumps are started, water enters storage tank 1 through the water injection main pipe 4.

[0047] The first variable-frequency water injection pump 2 and the second variable-frequency water injection pump 3 automatically adjust the running speed and output pressure of the pumps according to the real-time pressure data provided by the pressure transmitter 2-5 to ensure the stability of the system pressure. The pressure gauge 2-4 detects the pressure between the water injection main pipe and storage tank 1 in real time to ensure that the operator can monitor the pressure state of the system at any time.

[0048] When the device pressure exceeds the set value, the relief valve 2-3 will automatically release the excess pressure to prevent the system from overpressure.

[0049] A manual control valve 2-1, an electric control valve 2-2 and a relief valve 2-3 are installed in sequence between storage tank 1 and the first variable-frequency water injection pump 2. These valves can be quickly closed in case of emergencies to prevent liquefied petroleum gas from flowing back into the water injection main pipe. The first check valve 9-2 and the second check valve 10-2 are installed on the third water injection branch pipe 9 and the fourth water injection branch pipe 10 respectively to ensure that the water flow can only enter the storage tank unidirectionally and prevent liquefied petroleum gas from flowing back.

[0050] Swirl preventers 8 are installed on the first water injection branch pipe 6 and the second water injection branch pipe 7 to ensure that the water flow will not generate swirl during high-pressure water injection, maintain the stability and uniformity of the water flow, and improve the water injection effect and efficiency.

[0051] The first storage tank 1-1 and the second storage tank 1-2 are connected to the water injection main pipe 4 through independent third water injection branch pipe 9 and fourth water injection branch pipe 10. The independent connection between multiple storage tanks improves the redundancy and pressure management ability of the system.

[0052] When needed, the water injection volume of each storage tank can be independently controlled through the manual control valve and the electric control valve to ensure that the pressure of each storage tank is maintained within a safe range.

[0053] The low-point drain port 4-1 installed on the water injection main pipe 4 enables all pipelines and storage tanks in the water injection system to be quickly emptied when needed, facilitating system maintenance and repair and reducing the risks of corrosion and scaling. The water hammer arrester 4-2 installed on the water injection main pipe 4 can effectively absorb and relieve the water hammer impact caused by sudden valve closure or pump start and stop, protect the pipelines and equipment, and ensure the smooth operation of the system.

[0054] The high-pressure water injection device for the liquefied petroleum gas storage tank in this preferred embodiment realizes the stable control of the device pressure, prevents the backflow of liquefied petroleum gas, improves the water injection efficiency and stability, enhances the system safety and convenience, and ensures the safe, stable and efficient operation of the device.

[0055] The above embodiments are only explanations of the present invention, and they are not limitations of the present invention. Those skilled in the art can make modifications without creative contributions to this embodiment according to needs after reading this specification, but as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A high-pressure water injection device for a liquefied petroleum gas storage tank, characterized in that: The invention comprises a storage tank (1) and a first variable frequency water injection pump (2) and a second variable frequency water injection pump (3). The storage tank (1) is divided into two paths through a water injection main pipe (4) and is respectively connected to the first variable frequency water injection pump (2) and the second variable frequency water injection pump (3). The water injection main pipe (4) is provided with a manual control valve (2-1) and an electric control valve (2-2) in sequence.

2. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 1, characterized in that: The water injection main pipe (4) is provided with a relief valve (2-3), and a pressure gauge (2-4) is installed between the relief valve (2-3) and the storage tank (1).

3. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 1, characterized in that: A pressure transmitter (2-5) is provided between the first variable frequency water injection pump (2) and the second variable frequency water injection pump (3).

4. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 3, characterized in that: The first variable frequency water injection pump (2) is connected to the water injection pool (5) via a first water injection branch pipe (6), and the second variable frequency water injection pump (3) is connected to the water injection pool (5) via a second water injection branch pipe (7). Both the first water injection branch pipe (6) and the second water injection branch pipe (7) are equipped with a vortex preventer (8).

5. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 2, characterized in that: The storage tank (1) comprises a first storage tank (1-1) and a second storage tank (1-2); the first storage tank (1-1) is connected to a water injection main pipe (4) via a third water injection branch pipe (9); and the second storage tank (1-2) is connected to the water injection main pipe (4) via a fourth water injection branch pipe (10).

6. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 5, characterized in that: The third water injection branch pipe (9) is installed with a first root valve (9-1), a first check valve (9-2), a first electric control valve (9-3), and a first manual control valve (9-4) in sequence; the fourth water injection branch pipe (10) is installed with a second root valve (10-1), a second check valve (10-2), a second electric control valve (10-3), and a second manual control valve (10-4) in sequence.

7. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 6, characterized in that: The fourth water injection branch pipe (10) is located between the second root valve (10-1) and the second check valve (10-2) and is connected to the sewage branch pipe (11), and the sewage branch pipe (11) is installed with a third manual control valve (11-1).

8. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 5, characterized in that: The water injection main pipe (4) is provided with a low-point drain port (4-1), through which all pipes and the storage tank (1) are emptied.

9. The high-pressure water injection device for a liquefied petroleum gas storage tank according to claim 8, characterized in that: The water injection main pipe (4) is equipped with a water hammer absorber (4-2).

Images