A salt cavern gas storage halogen discharge pipe anti-crystallization control system and control method

Abstract

The application discloses a salt-cave gas storage brine discharge pipe anti-crystallization control system and a control method, and relates to the technical field of salt-cave gas storage. A plurality of sensing elements are arranged along the axial direction of the brine discharge pipe, and the sensing elements comprise temperature sensors and concentration sensors; the temperature sensors and the concentration sensors in the same sensing element simultaneously detect the temperature and the concentration of brine at the same point; and when it is determined that there is a risk of crystallization at any point, the control assembly prevents crystallization of the brine in the brine discharge pipe by means of dilution with fresh water. The application also discloses a control method, which calculates a crystallization risk coefficient of the brine by using the real-time temperature and the concentration of the brine detected by the temperature sensors and the concentration sensors, determines whether dilution is to be performed according to the size of the risk coefficient, changes passive removal of brine crystallization into active prevention, thereby inhibits the generation of crystallization in the brine discharge pipe, enables the brine discharge pipe to continuously discharge brine for a long time, and improves the brine discharge efficiency of the salt-cave gas storage.

Description

Technical Field

[0001] This invention relates to the field of salt cavern gas storage technology, and in particular to an anti-crystallization control system and control method for brine discharge pipes in salt cavern gas storage facilities. Background Technology

[0002] Salt cavern gas storage facilities are large caverns formed by water dissolution of underground salt rock layers, used to store energy media such as natural gas, hydrogen, or compressed air. Gas injection and brine removal are critical processes during salt cavern construction and subsequent operation, and their efficiency directly affects the construction period and operating costs of the salt cavern gas storage facility.

[0003] During the aeration and brine discharge process, the brine flowing within the discharge pipe is typically in a high salt concentration state (approaching or reaching saturation solubility). According to the phase equilibrium characteristics of brine, a decrease in temperature reduces its solubility for salts such as sodium chloride, leading to crystal precipitation on the inner surface of the discharge pipe. Further complicating matters, the natural unevenness of geothermal distribution within the underground salt rock layers (affected by factors such as geothermal gradients, differences in thermal conductivity of rock layers, and localized hydrothermal convection) results in significant temperature differences in the brine across different areas of the salt cavern. This means that brine crystallization within the discharge pipe does not occur in a fixed location but rather dynamically changes with the temperature field, potentially appearing randomly in multiple sections of the pipe.

[0004] Currently, existing technologies mainly focus on detection and removal strategies after crystallization occurs. For example, existing patent documents disclose sensor systems that detect the degree of blockage based on pressure difference or flow rate changes, combined with the injection of chemical solvents or mechanical scraping to unclog pipes. Some solutions slow down the crystallization rate by adjusting the brine discharge rate or brine concentration, but these are essentially passive responses or delayed adjustments. No technical solutions have yet been found that actively predict and intervene in, or prevent, crystal nucleation or growth before crystal formation. Summary of the Invention

[0005] The purpose of this invention is to provide an anti-crystallization control system and method for the brine discharge pipe of a salt cavern gas storage facility, in order to solve the problems existing in the prior art. By taking preventive measures before crystallization occurs, the brine in the discharge pipe is prevented from crystallizing, thereby improving the brine discharge efficiency of the salt cavern gas storage facility.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides an anti-crystallization control system for a brine discharge pipe of a salt cavern gas storage facility, comprising: a fresh water injection pipe and a brine discharge pipe sleeved outside the fresh water injection pipe; a flow regulating component and a water injection pump are provided at the top of the fresh water injection pipe; multiple water injection holes are provided on the side wall of the fresh water injection pipe, the multiple water injection holes are spaced apart along the axial direction of the fresh water injection pipe; the water injection pump is connected to the brine discharge pipe and the fresh water injection pipe through the water injection holes; multiple sensing elements are provided on the inner side wall of the brine discharge pipe, spaced apart along its axial direction, the sensing elements including a concentration sensor and a temperature sensor; The concentration sensor and temperature sensor are electrically connected to the control component, which controls the water injection pump and the flow regulation component to regulate the water injection flow rate of the injection hole.

[0007] In one embodiment, the diameter of the water injection hole gradually increases in the direction from the bottom of the fresh water injection pipe to the top of the fresh water injection pipe.

[0008] In one embodiment, the control component includes a data acquisition unit, a data processing unit, a control decision unit, and an execution control unit that are electrically connected in sequence. The data acquisition unit is electrically connected to a concentration sensor, a temperature sensor, and a flow sensor. The execution control unit is used to control the water injection pump and the flow regulation component.

[0009] In one embodiment, the freshwater injection pipe includes an inner pipe and an outer pipe sleeved outside the inner pipe. The outer pipe and the inner pipe are rotatably connected. The water injection pump is connected to the inner pipe. The bottom end of the inner pipe is closed. The flow regulating component is used to control the rotation of the inner pipe inside the outer pipe. The water injection holes include inner holes on the side wall of the inner tube and outer holes on the side wall of the outer tube, with the number and position of the inner holes and outer holes corresponding one-to-one.

[0010] In one embodiment, an ultrasonic anti-scaling device is also included. The ultrasonic anti-scaling device includes an ultrasonic generator installed on the ground and a plurality of ultrasonic transducers installed on the outer wall of the brine drain pipe. The plurality of ultrasonic transducers are spaced apart along the axial direction of the brine drain pipe, and the ultrasonic transducers are electrically connected to the ultrasonic generator via cables.

[0011] In one embodiment, the ultrasonic transducer operates at a frequency of 20 kHz ± 1 kHz.

[0012] In one embodiment, a data storage and communication module is further included, which is electrically connected to the control component and communicatively connected to the remote monitoring platform.

[0013] In one embodiment, the inner wall of the brine drain pipe is coated with an anti-crystallization coating.

[0014] A control method for an anti-crystallization control system based on the brine discharge pipe of a salt cavern gas storage facility, comprising the following steps: S1: Real-time acquisition of brine concentration and temperature data at each detection point is achieved by multiple concentration sensors and multiple temperature sensors spaced at intervals along the axial direction of the brine drain pipe. S2: The control component calculates the crystallization risk index at each detection point based on the collected data and compares it with the preset threshold to determine whether dilution intervention is required. S3: When dilution intervention is required, the control component sends a water injection flow command to the water injection pump and a water injection hole opening command to the flow regulation component, thereby starting the fresh water injection pipe to inject fresh water into the brine discharge pipe. S4: During the dilution process, the control component continuously monitors the changes in the crystallization risk index and dynamically adjusts the water injection flow rate according to the changing trend of the crystallization risk index.

[0015] In one embodiment, in step S2, when an ultrasonic transducer is installed on the side wall of the brine drain pipe, the ultrasonic transducer is used to generate ultrasonic waves and suppress crystal formation. The preset thresholds include a first preset threshold and a second preset threshold, with the first preset threshold being greater than the second preset threshold. When the crystallization risk index at any detection point is greater than or equal to the second preset threshold and less than the first preset threshold, it is determined that freshwater dilution intervention is required. When the crystallization risk index at all detection points is less than the second preset threshold and remains so for a predetermined time, it is determined that freshwater dilution intervention is stopped. When the crystallization risk index at any detection point is greater than or equal to the first preset threshold, it is determined that dual intervention of freshwater dilution and ultrasonic suppression is required.

[0016] The present invention achieves the following technical effects compared to the prior art: Multiple sensing elements, including concentration and temperature sensors, are installed on the inner wall of the brine discharge pipe. These elements are spaced apart along the axial direction of the pipe. The temperature sensor and the corresponding concentration sensor simultaneously detect the temperature and concentration of the brine at the same point and transmit the real-time temperature and concentration data to the control component. The control component determines whether the brine will crystallize based on the detected temperature and concentration. When a risk of crystallization is detected at any point, the control component activates the water injection pump and adjusts the opening of the water injection hole on the fresh water injection pipe through the flow regulating component. This adjusts the water injection flow rate of the pump into the brine discharge pipe through the water injection hole, thereby preventing brine crystallization in the discharge pipe through dilution with fresh water. In other words, the potential for crystallization is eliminated before it occurs, allowing the brine discharge pipe to continuously discharge brine for a long time and improving the brine discharge efficiency of the salt cavern gas storage.

[0017] A method for preventing crystallization is also disclosed. This method uses temperature and concentration sensors in the anti-crystallization control system to detect the real-time temperature and concentration of the brine and calculate the crystallization risk coefficient of the brine. The crystallization risk of the brine is judged while it is still in a crystallizing state. The higher the risk coefficient, the easier it is for the brine to crystallize at the corresponding temperature and concentration. At this time, it is necessary to regulate the flow rate of fresh water injected into the brine drain pipe through the control component, so as to dilute the brine before crystallization occurs and prevent crystallization. According to this anti-crystallization method, the state of the brine in the drain pipe can be predicted in real time, providing accurate data support for preventing brine crystallization, and transforming brine crystallization from passive removal to active prevention, thereby suppressing the occurrence of crystallization in the drain pipe. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the overall structure of the anti-crystallization control system in an embodiment of the present invention; Figure 2 for Figure 1 Enlarged schematic diagram of the structure at point A; Figure 3 This is a schematic diagram of the freshwater injection pipe in an embodiment of the present invention; The components include: 1. Salt cavern; 2. Air injection pipe; 3. Brine discharge pipe; 4. Freshwater injection pipe; 40. Outer pipe; 41. Inner pipe; 42. Sealing ring; 43. Outer hole; 44. Inner hole; 45. Limiting protrusion; 46. Limiting groove; 5. Surface sleeve; 6. Sensing element; 7. Flow sensor; 8. Data acquisition unit; 9. Data processing unit; 10. Control decision unit; 11. Execution control unit; 12. Water injection pump; 13. Flow regulating device; 14. Ultrasonic generator; 15. Data storage and communication module; 16. Remote monitoring platform; and 17. Ultrasonic transducer. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] The purpose of this invention is to provide an anti-crystallization control system and method for the brine discharge pipe of a salt cavern gas storage facility, in order to solve the problems existing in the prior art. By taking preventive measures before crystallization occurs, the brine in the discharge pipe is prevented from crystallizing, thereby improving the brine discharge efficiency of the salt cavern gas storage facility.

[0022] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0023] like Figures 1 to 2 As shown, this embodiment provides an anti-crystallization control system for the brine discharge pipe of a salt cavern gas storage facility, including a surface sleeve 5, an injection pipe 2, a brine discharge pipe 3, and a freshwater injection pipe 4, which are sequentially arranged. The freshwater injection pipe 4 is located inside the brine discharge pipe 3. During the injection of gas into the salt cavern 1, the brine in the salt cavern 1 flows out of the salt cavern 1 along the brine discharge pipe 3 under the action of gas pressure. Multiple sensing elements 6 are arranged on the inner wall of the brine discharge pipe 3. The sensing elements 6 include a concentration sensor and a temperature sensor. The multiple sensing elements 6 are spaced apart along the axial direction of the brine discharge pipe 3. The system simultaneously detects the temperature and concentration of brine at the same point on the brine discharge pipe 3 using both a temperature sensor and a concentration sensor in the same sensing element 6, and transmits the real-time temperature and concentration to the control component. The control component determines whether the brine will crystallize based on the detected temperature and concentration. During the process of discharging brine from the salt cavern 1 to the outside, temperature is a crucial factor affecting brine crystallization. The temperature is higher in the salt cavern 1, resulting in a higher brine concentration. As the brine flows towards the ground, the temperature at the bottom layer and the ground surface differs from that in the salt cavern 1. Due to significant temperature differences, when the temperature at the bottom layer and on the ground is lower than the temperature inside the salt cavern 1, the brine will crystallize due to the temperature drop. Therefore, after detecting the temperature and concentration of the brine using temperature and concentration sensors, the control component obtains the temperature of the brine and the concentration at the corresponding temperature (since the brine in the salt cavern 1 is saturated, after the temperature of the brine drops, the brine at any temperature is saturated, and the concentration at the corresponding temperature measured by the concentration sensor is the saturation at that temperature). The control component then uses this concentration to determine the risk of crystallization in the brine. When the risk of crystallization is detected at any point, the control component turns on the water injection pump 12 and adjusts the opening of the water injection hole on the fresh water injection pipe 4 through the flow regulating component. This adjusts the water injection flow rate of the water injection pump 12 into the brine discharge pipe 3 through the water injection hole, preventing the brine in the brine discharge pipe 3 from crystallizing by diluting it with fresh water. This eliminates the potential for crystallization before it occurs, allowing the brine discharge pipe 3 to continuously discharge brine for a long time and improving the brine discharge efficiency of the salt cavern 1 gas storage tank.

[0024] Salt cavern 1 is located underground. Generally, the temperature in salt cavern 1 is higher than the temperature of the bottom layer and the ground. However, it cannot be ruled out that the temperature of the brine in salt cavern 1 may be lower than the temperature of the bottom layer and the ground due to factors such as groundwater or surface air temperature. Therefore, multiple temperature sensors and multiple concentration sensors are installed at intervals along the axial direction on the inner wall of the brine discharge pipe 3 to detect the temperature and concentration at different locations in the brine discharge pipe 3, thereby ensuring that crystallization of the brine occurs at any location within the brine discharge pipe 3. In this embodiment, taking the gradual decrease in temperature of the brine as it is discharged from salt cavern 1 through the brine discharge pipe 3 as an example, since the temperature of the brine decreases closer to the ground, the solubility of the solutes in the brine gradually decreases, making it easier for the brine to crystallize closer to the ground in the brine discharge pipe 3. The risk of crystallization is greatest in the brine injection pipe 4. Therefore, the diameter of the injection holes on the pipe gradually increases from bottom to top. Specifically, the injection hole at the end of the pipe 4 closest to the bottom of the salt cave 1 has the smallest diameter, and the diameter of the injection holes gradually increases as the pipe 4 extends towards the ground. When the control component detects a risk of brine crystallization, the flow regulation component adjusts the opening of the injection holes. Because the injection holes near the ground have a larger diameter, they inject fresh water into the brine discharge pipe 3 at a larger flow rate. Meanwhile, the injection holes near the bottom of the salt cave 1 have a smaller diameter, resulting in a lower flow rate at these locations. This suppresses crystallization in the lower-risk areas of the brine discharge pipe 3. This method can suppress brine crystallization in the discharge pipe 3 while also saving fresh water.

[0025] In the above, the control component needs to collect the detection values ​​of each concentration sensor and each temperature sensor, and also needs to compare multiple values ​​and calculate the crystallization risk. In this embodiment, the control component includes a data acquisition unit 8, a data processing unit 9, a control decision unit 10, and an execution control unit 11 connected in sequence. The data acquisition unit 8 is used to collect the real-time detection values ​​of the temperature sensor and the concentration sensor. The data processing unit 9 calculates the crystallization risk of each point in the brine drain pipe 3 based on the real-time detection values ​​collected by the data acquisition unit 8. The control decision unit 10 compares the crystallization risk of each point in the brine drain pipe 3 based on the crystallization risk and selects the position with the highest crystallization risk. The execution control unit 11 controls the water injection pump 12 and the Luliang regulating device based on the highest crystallization risk to control the water injection flow rate of the water injection hole.

[0026] Preferably, the control component is a general-purpose microcontroller (MCU), such as the STM32 series.

[0027] A flow sensor 7 is installed at the ground-level end of the brine drain pipe 3. The flow sensor 7 detects the brine discharge flow rate in the brine drain pipe 3. If brine crystallization occurs in the brine drain pipe 3, it will inevitably affect the discharge flow rate. Therefore, the flow sensor 7 is used to determine the inhibitory effect of water dilution and ultrasonic vibration on crystallization in the brine drain pipe 3. If the flow sensor 7 detects that the brine discharge flow rate reaches the predetermined flow rate and remains constant, it proves that water dilution and ultrasonic vibration can inhibit brine crystallization. However, if the flow sensor 7 detects that the brine discharge flow rate continues to decrease, it proves that water dilution and ultrasonic vibration have not inhibited brine crystallization or that water dilution and ultrasonic vibration alone are no longer sufficient to inhibit brine crystallization. In this case, gas injection needs to be stopped, the brine drain pipe 3 needs to be dismantled and the crystals cleaned before resuming gas injection.

[0028] refer to Figure 3 The freshwater injection pipe 4 includes an inner pipe 41, with one end of the inner pipe 41 closed near the bottom of the salt cave 1. The inner pipe 41 is connected to a flow regulating device 13. An outer pipe 40 is fitted around the outer side of the inner pipe 41. The flow regulating device 13 drives the inner pipe 41 to rotate within the outer pipe 40. The water injection hole includes an inner hole 44 on the inner pipe 41 and an outer hole 43 on the outer pipe 40. The number and position of the inner holes 44 and the outer holes 43 correspond one-to-one, and the corresponding outer holes 43 have the same diameter as the inner holes 44. Sealing rings 42 are embedded on the inner surface of the inner pipe 41 and the outer surface of the outer pipe 40. The width of the sealing rings 42 is greater than the diameter of the water injection hole. The sealing rings 42 on the inner surface of the inner pipe 41 and the sealing rings 42 on the outer surface of the outer pipe 40 provide rotational sealing. The sealing rings 42 on the outer pipe 40 are positioned corresponding to the outer holes 43 and are arranged accordingly. Water outlets are provided at the corresponding positions of the sealing ring 42 and the inner hole 44 on the inner tube 41. The diameters of the water outlets are equal to those of the corresponding outer hole 43 and inner hole 44. The output end of the water pump 12 is connected to the inner tube 41. When it is not necessary to input fresh water into the brine discharge pipe 3, the inner tube 41 is rotated by the flow regulating device 13 to make the inner hole 44 and the outer hole 43 misaligned. At this time, the fresh water injection pipe 4 and the brine discharge pipe 3 are not connected. The sealing ring 42 seals the gap between the inner tube 41 and the outer tube 40 to avoid waste of fresh water. When it is necessary to inject fresh water into the brine discharge pipe 3, the flow regulating device 13 drives the inner tube 41 to rotate, and the inner hole 44, the water outlet and the outer hole 43 are connected. Fresh water enters the inner tube 41 and is injected into the brine discharge pipe 3 along the path of the inner hole 44, the water outlet and the outer hole 43 to dilute the brine in the brine discharge pipe 3, thereby inhibiting the crystallization of the brine.

[0029] Preferably, an annular limiting protrusion 45 is provided on the inner side wall of the outer tube 40, and a limiting groove 46 is provided on the inner tube 41. The limiting protrusion 45 is locked in the limiting groove 46 to prevent axial displacement between the inner tube 41 and the outer tube 40, thereby ensuring that the axis of the inner hole 44 coincides with the axis of the corresponding outer hole 43, and ensuring that fresh water smoothly enters the brine drain pipe 3.

[0030] The flow regulating device 13 includes a geared motor, the output shaft of which is connected to the inner tube 41. When the geared motor is turned on, it drives the inner tube 41 to rotate in the outer tube 40, thereby adjusting the opening of the water injection hole.

[0031] Furthermore, since one end of the fresh water injection pipe 4 needs to extend to the bottom of the salt cave 1, it is ensured that the water injection range of the injection hole can cover the entire brine drain pipe 3. This prevents the stored gas from causing changes in the brine temperature during the gas storage process, which could lead to crystallization in the brine drain pipe 3. In order to facilitate maintenance in case of a malfunction in the inner pipe 41, both the inner pipe 41 and the outer pipe 40 are complete pipe bodies. That is, when the flow regulating device 13 adjusts the flow rate, the inner pipe 41 rotates as a whole inside the outer pipe 40. Combined with the gradual expansion of the injection hole diameter along the direction extending from the bottom to the top of the fresh water injection pipe 4, while suppressing crystallization at the location with the greatest risk (taking the case where the closer to the ground, the greater the risk of crystallization) as an example, fresh water is injected into other locations at a smaller flow rate. This achieves the purpose of suppressing crystallization in the entire brine drain pipe 3, while also saving the amount of fresh water used.

[0032] Since the flow rate of fresh water injected into the brine drain pipe 3 through the fresh water injection pipe 4 is limited, even when all the water injection holes are adjusted to the maximum flow rate (i.e., the inner hole 44 and the outer hole 43 are all aligned), the brine cannot be diluted in time, and crystals will still form on the inner wall of the brine drain pipe 3. In this embodiment, an ultrasonic anti-scaling device is also included. An ultrasonic generator 14 is installed on the ground, and multiple ultrasonic transducers 17 are installed on the wall of the brine drain pipe 3. The working frequency of the ultrasonic transducers 17 is 20kHz±1kHz. The ultrasonic transducers 17 are spaced apart along the axial direction of the brine drain pipe 3. After the flow regulating device 13 adjusts the water injection hole to the maximum flow rate, the execution control unit 11 turns on the ultrasonic generator 14. The ultrasonic generator 14 converts the mains power into a high-frequency electrical signal. The ultrasonic transducers 17 convert the electrical signal into mechanical vibration (ultrasound), thereby vibrating the brine drain pipe 3 and shaking off the crystals that have formed on the wall of the brine drain pipe 3, achieving the anti-crystallization purpose of combining pre-crystallization inhibition and post-crystallization removal.

[0033] To improve the anti-crystallization effect on the inner wall of the brine drain pipe 3, an anti-crystallization coating is applied to the inner wall of the brine drain pipe 3. The anti-crystallization coating includes, but is not limited to, fluoropolymers (such as PTFE, FEP, fluorosilicone modified resin), non-metallic inorganic materials (such as SiO2-based sol-gel coating), etc. The specific coating material is customized according to the brine composition, brine temperature, and brine draining rate.

[0034] In another technical solution, vortex generators are installed on the inner wall of the brine drain pipe 3, with one group arranged every 20 to 50 m along the axial direction of the brine drain pipe 3. Each group of vortex generators contains 3 to 6 units, which are evenly distributed along the circumference of the brine drain pipe 3, and adjacent groups are axially staggered by a certain angle (such as 30° to 60°) to cover the entire cross-section of the brine drain pipe 3.

[0035] Vortex generators include spiral guide groove type and fixed guide vane type.

[0036] Spiral guide channel type: The brine discharge pipe 3 has spiral ribs on its wall. The height of the ribs is 3% to 5% of the inner diameter of the pipe, and the width is 5 to 10 mm. The spiral angle (the angle between the spiral ribs and the axis of the brine discharge pipe 3) is 15° to 30°, forming a single-start or multi-start thread. When the brine flows upward, it is forced to generate a tangential velocity component along the spiral ribs, forming an overall rotating upward vortex. The vortex enhances the radial mixing of fresh water and brine, avoiding excessively high local concentrations. At the same time, centrifugal force throws high-concentration brine towards the pipe wall, making it easier for fresh water to mix in the central area, thereby inhibiting the crystallization process of the brine.

[0037] Fixed guide vane type: Multiple sets are arranged at intervals along the axial direction of the brine drain pipe 3. When multiple sets are arranged along the axial direction, the blades of each set rotate in the same direction (both right-handed or left-handed) to avoid the opposite vortices canceling each other out.

[0038] Each group consists of 3-6 fixed blades, with an axial length of 10-20 cm and a radial height of 10%-20% of the inner diameter of the brine discharge pipe 3. Interference between the blades and the freshwater injection pipe must be avoided. The leading edge of the guide blades is welded to the pipe wall or threaded, while the trailing edge is free. The angle (angle of attack) between the blade and the pipe axis is 20°-40°. The blades in the same group are evenly distributed circumferentially along the brine discharge pipe 3, with a flow gap of 2-3 times the blade width between adjacent blades. When the brine passes through the blades, a strong swirling flow is generated, forming a vortex zone downstream of the blades. Within the effective range of the vortex, the freshwater is rapidly mixed after injection, and the shear force is sufficient to inhibit crystal nuclei from adhering to the pipe wall and to inhibit brine crystals from adhering to the surface of the brine discharge pipe 3, thereby achieving the purpose of preventing brine crystallization.

[0039] Preferably, the blade surface can be machined with micro-turbulence pits (2-3 mm in diameter and 0.5 mm in depth) to enhance local turbulence.

[0040] The data acquisition, processing, and execution processes in the control component are all stored in the data storage and communication module 15, and all data signals related to water dilution are transmitted to the remote monitoring platform 16 through the communication module, providing data support for the computer to optimize the dilution strategy.

[0041] This embodiment also discloses a control method for an anti-crystallization control system for the brine discharge pipe of a salt cavern 1 gas storage tank, comprising the following steps: S1: Multiple concentration sensors and multiple temperature sensors are spaced apart along the axial direction of the brine drain pipe 3. At each detection point, one concentration sensor and one temperature sensor are installed to collect the concentration data and temperature data of the brine at the corresponding detection point in real time; and the temperature data and concentration data detected at each detection point are transmitted to the control component. S2: The control component calculates the crystallization risk index at each detection point based on the collected data and compares it with the preset threshold to determine whether dilution intervention is required. The formula for calculating the crystallization risk index is as follows: in, Ci For the first i Crystallization risk index at each testing point c i The concentration of brine in salt cavern 1. c sat （T i ） The concentration (i.e. saturation) at each detection point in the brine drain pipe 3 at the corresponding temperature. α i For safety factor, and α i The flow rate increases from bottom to top along the three axes of the brine drain pipe. α i Take values ​​of 0.1, 0.2, 0.3, ... α i The number of values ​​is equal to the number of temperature sensors or concentration sensors.

[0042] Calculation of preset thresholds: Samples of brine are taken from salt cavern 1. The sample temperature is adjusted in the laboratory to be equal to the temperature in salt cavern 1 to ensure that the sample reaches saturation at the temperature of salt cavern 1. The sample temperature is adjusted according to the temperature distribution in the bottom layer where the brine drain pipe 3 is located and the ground temperature during gas storage. The bottom layer temperature data can be obtained by a temperature sensor installed in the brine drain pipe, thereby obtaining the concentration of brine at saturation at different temperatures. Substituted into the above formula, the crystallization risk index at different temperatures is calculated, and one-third of the risk index is taken as the first preset threshold at that temperature. The risk index is used as the second preset threshold at that temperature. If the first preset threshold is less than the second preset threshold, it means that the solubility of brine corresponding to the first preset threshold is greater than the solubility of brine corresponding to the second preset threshold.

[0043] Preferably, an ultrasonic transducer 17 is also provided on the inner wall of the brine drain pipe 3. The third preset threshold is taken as two-thirds of the second preset threshold. If the crystallization risk index at any detection point is greater than the second preset threshold, the control decision unit 10 generates an ultrasonic start command again and the execution control unit 11 starts the ultrasonic generator 14 to remove the crystals on the brine drain pipe 3 through vibration.

[0044] S3: When dilution intervention is required, the control component sends a water injection flow command to the water injection pump 12 and a water injection hole opening command to the flow regulation component, and starts the fresh water injection pipe 4 to inject fresh water into the brine discharge pipe 3. Specifically, during the dilution process using fresh water, the control decision unit 10 in the control component compares the crystallization risk index at each detection point with the first preset threshold to determine whether dilution intervention is required. If the crystallization risk index at any detection point is greater than or equal to the first preset threshold and less than the second threshold, the control decision unit 10 generates a dilution start command, and the execution control unit 11 starts the water injection pump 12 and the flow regulating device 13 to inject fresh water into the brine drain pipe 3 for dilution; if the crystallization risk index at any detection point is less than the first preset threshold, it means that the brine will not crystallize. At this time, the control decision unit 10 generates a dilution stop command, and the execution control unit 11 shuts down the water injection pump 12 and the flow regulating device 13 closes the water injection hole.

[0045] Based on the installation of an ultrasonic transducer 17 on the brine drain pipe 3, if the crystallization risk index at any detection point is greater than the second preset threshold, the freshwater dilution process is maintained, the control decision unit 10 generates an ultrasonic start command, and the execution control unit 11 starts the ultrasonic generator 14 to remove crystals on the brine drain pipe 3 through vibration; when the two processes of vibration to remove crystals and dilution to inhibit crystal formation are carried out simultaneously, if the crystallization risk index at any detection point is less than the third preset threshold, the control decision unit 10 generates an ultrasonic stop command again, the execution control unit 11 shuts down the ultrasonic generator 14, and the freshwater dilution to inhibit crystal formation process is maintained until the crystallization risk index at any detection point is less than the first preset threshold.

[0046] S4: During the freshwater dilution process, the control component continuously monitors the changes in the crystallization risk index. With the continuous injection of freshwater and the vibration of the ultrasonic transducer 17, the degree of crystallization in the brine discharge pipe 3 decreases. Meanwhile, the temperature sensor and concentration sensor continuously monitor the temperature and concentration of the brine during the process of suppressing crystallization. The control component calculates the crystallization risk index based on the real-time temperature and concentration and adjusts the water injection flow rate and the power of the ultrasonic transducer 17 in real time to reduce the consumption of freshwater and electricity.

[0047] Any adaptive changes made according to actual needs are within the scope of protection of this invention.

[0048] It should be noted that, for those skilled in the art, it is obvious that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0049] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A crystallization prevention control system for brine discharge pipes in salt cavern gas storage facilities, characterized in that, include: A freshwater injection pipe (4) and a brine discharge pipe (3) sleeved on the outside of the freshwater injection pipe (4). The top of the freshwater injection pipe (4) is provided with a flow regulating component and a water injection pump (12). Multiple water injection holes are provided on the side wall of the freshwater injection pipe (4). The multiple water injection holes are spaced apart along the axial direction of the freshwater injection pipe (4). The water injection pump (12) is connected to the gap between the brine discharge pipe (3) and the freshwater injection pipe (4) through the water injection holes. Multiple sensing elements (6) are provided on the inner side wall of the brine discharge pipe (3) spaced apart along its axial direction. The sensing elements (6) include a concentration sensor and a temperature sensor. The concentration sensor and the temperature sensor are electrically connected to the control component, which is used to control the water injection pump (12) and the flow regulating component to regulate the water injection flow rate of the water injection hole.

2. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, The diameter of the water injection hole gradually increases along the direction from the bottom of the fresh water injection pipe (4) to the top of the fresh water injection pipe (4).

3. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, The control component includes a data acquisition unit (8), a data processing unit (9), a control decision unit (10), and an execution control unit (11) connected in sequence. The data acquisition unit (8) is electrically connected to the concentration sensor, the temperature sensor, and the flow sensor (7). The execution control unit (11) is used to control the water injection pump (12) and the flow regulation component.

4. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, The freshwater injection pipe (4) includes an inner pipe (41) and an outer pipe (40) sleeved outside the inner pipe (41). The outer pipe (40) is rotatably connected to the inner pipe (41). The water injection pump (12) is connected to the inner pipe (41). The bottom end of the inner pipe (41) is closed. The flow regulating component is used to control the rotation of the inner pipe (41) inside the outer pipe (40). The water injection hole includes an inner hole (44) on the side wall of the inner tube (41) and an outer hole (43) on the side wall of the outer tube (40), and the number and position of the inner hole (44) and the outer hole (43) correspond one-to-one.

5. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, It also includes an ultrasonic anti-scaling device, which includes an ultrasonic generator (14) installed on the ground and multiple ultrasonic transducers (17) installed on the outer wall of the brine drain pipe (3). The multiple ultrasonic transducers (17) are spaced apart along the axial direction of the brine drain pipe (3). The ultrasonic transducers (17) are electrically connected to the ultrasonic generator (14) via cables.

6. The anti-crystallization control system for the brine discharge pipe of a salt cavern gas storage facility according to claim 5, characterized in that, The ultrasonic transducer (17) operates at a frequency of 20kHz ± 1kHz.

7. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, It also includes a data storage and communication module (15), which is electrically connected to the control component and communicates with the remote monitoring platform (16).

8. The anti-crystallization control system for the brine discharge pipe of the salt cavern gas storage facility according to claim 1, characterized in that, The inner wall of the brine drain pipe (3) is coated with an anti-crystallization coating.

9. A control method for an anti-crystallization control system based on the brine discharge pipe of a salt cavern gas storage facility according to any one of claims 1 to 8, characterized in that, Includes the following steps: S1: The concentration and temperature data of the brine at each detection point are collected in real time by a plurality of concentration sensors and a plurality of temperature sensors that are spaced apart along the axial direction of the brine drain pipe (3); S2: The control component calculates the crystallization risk index at each detection point based on the collected data, and compares it with a preset threshold to determine whether dilution intervention is required; S3: When dilution intervention is required, the control component sends a water injection flow command to the water injection pump (12) and sends a water injection hole opening command to the flow regulation component to start the fresh water injection pipe (4) to inject fresh water into the brine discharge pipe (3); S4: During the dilution process, the control component continuously monitors the changes in the crystallization risk index and dynamically adjusts the water injection flow rate according to the changing trend of the crystallization risk index.

10. The control method according to claim 9, characterized in that, In step S2, when an ultrasonic transducer (17) is installed on the side wall of the brine drain pipe (3), the ultrasonic transducer (17) is used to generate ultrasonic waves and suppress crystal formation. The preset threshold includes a first preset threshold and a second preset threshold, wherein the first preset threshold is greater than the second preset threshold; When the crystallization risk index at any detection point is greater than or equal to the second preset threshold and less than the first preset threshold, it is determined that freshwater dilution intervention is required. When the crystallization risk index at all detection points is less than the second preset threshold and remains so for a predetermined time, it is determined that the freshwater dilution intervention will be stopped; when the crystallization risk index at any detection point is greater than or equal to the first preset threshold, it is determined that a dual intervention of freshwater dilution and ultrasonic suppression is required.

Images