Automatic plugging method and device for gas leakage in loading process of lower loading arm

Abstract

The invention provides an automatic plugging method and device for gas leakage in the loading process of a lower loading arm, and relates to the technical field of petrochemical product loading, and the method comprises the following steps: in the loading process, collecting two groups of core parameters in real time through a detection module: VOCs concentration C at a loading arm sealing interface in a loading area, and pressure difference delta P between the interior of a loading arm sealing cavity and the atmosphere; meanwhile, the real-time flow V in the gas phase recovery pipe is collected; by collecting multi-dimensional parameters of the VOCs concentration, the pressure difference of the sealing cavity and the gas-phase recovery flow in real time and combining with an algorithm of introducing correction coefficients such as medium types, environment temperature and altitude, the leakage amount can be quantitatively calculated, threshold judgment is achieved, closed-loop iteration adjustment with the period of 1-3 seconds is matched, it is ensured that the plugging force and the recovery flow are precisely matched with the leakage state, and the sealing performance of the gas-phase recovery flow is improved. Compared with traditional manual inspection, the response speed is increased by dozens of times, and the VOCs leakage rate of media such as benzene can be controlled to be far lower than the limit value.

Description

Technical Field

[0001] This invention relates to the field of petrochemical product loading technology, and in particular to a method and device for automatically sealing gas leakage during loading of bottom loading arms. Background Technology

[0002] In the petrochemical industry, aromatic hydrocarbons such as benzene are highly volatile, and improper sealing during loading can easily lead to VOCs leakage. Currently, the industry generally uses bottom-loading arms instead of traditional top-loading arms, and equips them with gas phase recovery devices to introduce volatile VOCs into an RTO for treatment, thereby reducing atmospheric emissions. Bottom-loading arms transport the medium through liquid phase pipes and recover volatile gases through gas phase pipes. The tightness of the sealing interface is crucial for controlling leakage. However, in actual loading processes, deviations in the ovality of the tank truck interface, wear or aging of the loading arm seals can still lead to minor or even substantial leakage, especially when loading pressure fluctuates, further increasing the risk of leakage. Existing leak control methods for bottom loading arms largely rely on a "passive sealing + periodic maintenance" approach: seals need to be replaced manually on a regular basis, and leak detection is mainly achieved through manual inspections, resulting in problems such as detection lag and untimely response. When a sudden leak occurs, the process of manually shutting down the loading pump and manually tightening the seal is time-consuming, during which a large amount of VOCs still diffuses into the environment. This not only fails to meet VOCs emission limits but may also lead to safety accidents such as explosions and personnel poisoning due to benzene vapor accumulation. It also causes material loss and reduces the economic efficiency of loading. Therefore, this invention proposes an automatic gas leak sealing method and device during the loading process of bottom loading arms to solve the problems existing in the prior art. Summary of the Invention

[0003] To address the aforementioned issues, this invention proposes an automatic gas leakage sealing method and device during the loading of bottom loading arms. By real-time acquisition of multi-dimensional parameters such as VOCs concentration, sealing cavity pressure difference, and gas phase recovery flow rate, combined with an algorithm incorporating correction coefficients based on media type, ambient temperature, and altitude, the leakage amount can be quantitatively calculated and threshold judgment can be achieved. With closed-loop iterative adjustment in a 1-3 second cycle, the sealing force and recovery flow rate are precisely matched to the leakage state, improving the response speed by tens of times compared to traditional manual inspection. This method can control the VOCs leakage of media such as benzene to a level far below the limit.

[0004] To achieve the objectives of this invention, the invention is implemented through the following technical solution: an automatic gas leakage sealing method during the loading of loading arms, comprising the following steps: S1: During the loading process, two sets of core parameters are collected in real time through the detection module: VOCs concentration C at the loading arm sealing interface and pressure difference ΔP between the loading arm sealing cavity and the atmosphere. At the same time, the real-time flow rate V1 in the gas phase recovery pipe is collected. S2: The control module calls the preset algorithm to calculate the real-time leakage amount Q, compares Q with the preset leakage threshold Q0. When Q≤Q0, the current loading and gas phase recovery status is maintained. When Q>Q0, it is determined that the state needs to be sealed and S3 is executed. S3: The control module sends a command to the sealing mechanism to drive the sealing mechanism to apply a sealing force F to the sealing interface of the loading arm, and at the same time sends a command to the flow regulation component on the gas phase recovery pipe to adjust the recovery flow to the target value V. S4: Continuously collect VOCs concentration C', pressure difference ΔP', and recovery flow rate V' after plugging, recalculate the leakage Q', maintain the current plugging force and recovery flow rate when Q'≤Q0, and iteratively adjust the plugging force F and recovery flow rate V until Q'≤Q0, then return to S2 for continuous monitoring.

[0005] A further improvement is made in S2, where the algorithm for calculating the leakage amount Q is as follows: Q = K × C × ΔP × S, Where: K is the correction factor, which is 1.2-1.5 depending on the medium type - benzene, and 1.0 when the ambient temperature is -25℃, with an increase of 0.1 correction for every 10℃ increase; C is the VOCs concentration, in mg / m³; ΔP is the pressure difference between the loading arm sealing cavity and the atmosphere, in Pa, ΔP=P1-P0, where P1 is the pressure inside the loading arm sealing cavity and P0 is the atmospheric pressure; S is the effective sealing area of ​​the loading arm sealing interface, in m², which is preset by the loading arm model.

[0006] A further improvement is made in the following: In S3, the calculation algorithm for the blocking force F is as follows: F = K1 × Q × P0, Where: K1 is the force correction coefficient, set according to the type of sealing mechanism; Q is the real-time leakage calculated in S2, in mg / h; P0 is the atmospheric pressure, in Pa, used to correct the sealing force requirements at different altitudes.

[0007] A further improvement is made in S3, where the algorithm for calculating the target recovery flow rate V is as follows: V = K2 × Q + V0, Where: K2 is the flow correction coefficient (unit: m³·h⁻¹ / mg·h⁻¹), set according to the RTO processing capacity; Q is the real-time leakage calculated in S2 (unit: mg / h); V0 is the basic recovery flow rate (unit: m³ / h), which is the minimum recovery flow rate when the vehicle is stable, to avoid frequent start-up and shutdown of the recovery system.

[0008] A further improvement is that in S4, the iterative adjustment period is 1-3 seconds, and the change in the blocking force F during each adjustment does not exceed 10% of the initial value, and the change in the recovery flow rate V does not exceed 15% of the initial value.

[0009] An automatic gas leakage sealing device during loading of a bottom-loading arm includes a loading arm body, a detection module, a sealing mechanism, a control module, and an auxiliary monitoring unit. The loading arm body has a liquid medium conveying channel and a gas phase recovery pipe. The liquid medium conveying channel is used to convey the medium to be loaded to the tank truck, and the gas phase recovery pipe is used to discharge volatile gases to the exhaust gas treatment system. The detection module includes a VOCs sensor for detecting the VOCs concentration at the sealing interface, a pressure sensor for detecting the pressure parameters inside the loading arm body, and a data acquisition unit for processing the sensor signals. The sealing mechanism includes an adjustable sealing component that mates with the sealing interface and a drive component that expands the adjustable sealing component to achieve sealing adjustment. The control module is electrically connected to the data acquisition unit, the drive component, and the flow adjustment component on the gas phase recovery pipe, and has built-in algorithms for calculating leakage, controlling sealing force, and adjusting recovery flow. The auxiliary monitoring unit includes a flow sensor for monitoring flow parameters in the gas phase recovery pipe and a temperature sensor for monitoring medium temperature parameters, and its signal output terminal is connected to the control module.

[0010] A further improvement is that the VOCs sensor is a catalytic combustion sensor with a detection range of 0-1000 mg / m³, and the VOCs sensor is located on the outside of the sealed interface, 5-10 cm away from the interface.

[0011] A further improvement is that the adjustable sealing assembly includes an inner sealing ring and a flexible sealing bladder. The inner sealing ring is used to directly fit with the sealing interface, and the flexible sealing bladder is located above the inner sealing ring and connected to the driving component. The inner sealing ring is made of oil-resistant nitrile rubber or fluororubber, and the driving component is an air pump.

[0012] A further improvement is that the control module is a PLC controller and is equipped with an alarm unit. When the detected leakage exceeds the preset emergency threshold, the alarm unit issues an audible and visual alarm and sends a shutdown signal to the loading pump control system.

[0013] A further improvement is that the flow regulation component on the gas phase recovery pipe is an electric proportional regulating valve, which works in conjunction with the control module to adjust the recovery flow rate in real time.

[0014] The beneficial effects of this invention are as follows: 1. This invention collects multi-dimensional parameters such as VOCs concentration, sealing cavity pressure difference, and gas phase recovery flow rate in real time. Combined with an algorithm that incorporates correction coefficients for media type, ambient temperature, altitude, etc., it can quantitatively calculate the leakage amount and achieve threshold judgment. With closed-loop iterative adjustment with a cycle of 1-3 seconds, it ensures that the sealing force and recovery flow rate are accurately matched to the leakage state. Compared with traditional manual inspection, the response speed is improved by tens of times, and it can control the VOCs leakage of media such as benzene to a level far below the limit.

[0015] 2. This invention, through the synergistic design of a dual sealing structure of inner sealing ring + flexible sealing bladder, catalytic combustion-type close-range VOCs sensor and electric proportional regulating valve, is not only adaptable to different wear interfaces, altitude temperature and medium viscosity conditions, but also avoids the risk of leakage caused by the failure of a single component, making the VOCs recovery efficiency more stable and fully meeting environmental emission requirements.

[0016] 3. The PLC emergency shutdown alarm function of the control module of this invention can quickly cut off the loading process when the leakage exceeds the emergency threshold, which greatly reduces the risk of explosion and personnel poisoning caused by benzene vapor accumulation; the automated operation of the device reduces the frequency of manual inspection, the double sealing structure extends the replacement cycle of the seals, and the dynamic adjustment of the recovery flow avoids energy waste, which is both practical and has promotional value. Attached Figure Description

[0017] Figure 1 This is a flowchart of the present invention; Figure 2 This is a schematic diagram of the main body of the loading arm of the present invention.

[0018] The components include: 1. Liquid medium transport channel; 2. Gas phase recovery pipe; 3. Drive component; 4. Inner sealing ring; 5. Flexible sealing bladder; 6. Flow sensor; 7. Sealing interface; 8. Control module; 9. Electric proportional regulating valve. Detailed Implementation

[0019] To enhance understanding of the present invention, the present invention will be further described in detail below with reference to embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention. Example 1

[0020] according to Figure 1 , 2 As shown in the figure, this embodiment proposes an automatic gas leakage sealing method during the loading of bottom loading arms, including the following steps: S1: During the loading process, two sets of core parameters are collected in real time through the detection module: VOCs concentration C at the loading arm sealing interface and pressure difference ΔP between the loading arm sealing cavity and the atmosphere. At the same time, the real-time flow rate V1 in the gas phase recovery pipe is collected. S2: The control module calls a preset algorithm to calculate the real-time leakage amount Q, compares Q with the preset leakage threshold Q0. If Q ≤ Q0, maintain the current loading and gas phase recovery status; if Q > Q0, it is determined that a sealing state is required, and S3 is executed. The algorithm for calculating the leakage amount Q is as follows: Q = K × C × ΔP × S, Where: K is the correction coefficient, which is 1.2-1.5 depending on the medium type (benzene) and 1.0 at an ambient temperature of -25℃, increasing by 0.1 for every 10℃ increase; C is the VOCs concentration, in mg / m³; ΔP is the pressure difference between the loading arm's sealing cavity and the atmosphere, in Pa, ΔP=P1-P0, where P1 is the pressure inside the loading arm's sealing cavity and P0 is the atmospheric pressure; S is the effective sealing area of ​​the loading arm's sealing interface, in m², preset by the loading arm model. The algorithm incorporates corrections based on medium type and ambient temperature, adapting leakage calculations to different operating conditions and improving accuracy; the parameters are clearly defined and quantifiable, facilitating algorithm reuse and adjustment in different scenarios.

[0021] S3: The control module sends a command to the sealing mechanism to apply a sealing force F to the loading arm sealing interface, and simultaneously sends a command to the flow regulation component on the gas phase recovery pipe to adjust the recovery flow rate to the target value V; the calculation algorithm for the sealing force F is as follows: F = K1 × Q × P0, Where: K1 is the force correction coefficient, set according to the type of sealing mechanism; Q is the real-time leakage calculated in S2, in mg / h; P0 is the atmospheric pressure, in Pa, used to correct the sealing force requirements at different altitudes; combining atmospheric pressure to correct the sealing force enables the device to maintain the best sealing effect in high-altitude areas, making it more applicable; the sealing force is positively correlated with the leakage, avoiding wear of the seals caused by excessive sealing and extending the service life of the components; The algorithm for calculating the target recycling flow V is as follows: V = K2 × Q + V0, Where: K2 is the flow correction coefficient (unit: m³·h⁻¹ / mg·h⁻¹), set according to the RTO processing capacity; Q is the real-time leakage amount calculated in S2 (unit: mg / h); V0 is the basic recovery flow rate (unit: m³ / h), which is the minimum recovery flow rate when the vehicle is stable, avoiding frequent start-ups and shutdowns of the recovery system; the recovery flow rate is dynamically adjusted according to the leakage amount, ensuring full recovery of VOCs while avoiding energy waste caused by excessive flow rate; the basic flow rate V0 setting reduces the number of system start-ups and shutdowns, lowers the equipment failure rate, and extends the life of the recovery system; S4: Continuously collect VOCs concentration C', pressure difference ΔP', and recovery flow rate V' after sealing, recalculate the leakage Q'. When Q' ≤ Q0, maintain the current sealing force and recovery flow rate. When Q' > Q0, iteratively adjust the sealing force F and recovery flow rate V until Q' ≤ Q0, then return to S2 for continuous monitoring. The iterative adjustment cycle is 1-3 seconds. Each adjustment should not exceed 10% of the initial value for the sealing force F and 15% of the initial value for the recovery flow rate V. Short-cycle adjustment allows for rapid response to changes in the sealing state, ensuring the leakage quickly returns to within the threshold; small-amplitude adjustments avoid the impact of sudden parameter changes on the loading system, ensuring the stability of media delivery.

[0022] An automatic gas leakage sealing device during loading of a bottom-loading arm includes a loading arm body, a detection module, a sealing mechanism, a control module 8, and an auxiliary monitoring unit. The loading arm body has a liquid medium conveying channel 1 and a gas phase recovery pipe 2. The liquid medium conveying channel 1 is used to convey the medium to be loaded to the tank truck, and the gas phase recovery pipe 2 is used to discharge volatile gases to the exhaust gas treatment system. The detection module includes a VOCs sensor for detecting the VOCs concentration at the sealing interface 7, a pressure sensor for detecting the pressure parameters inside the loading arm body, and a data acquisition unit for processing the sensor signals. The sealing mechanism includes an adjustable sealing component that mates with the sealing interface and a drive component 3 that expands the adjustable sealing component to achieve sealing adjustment. The control module 8 is electrically connected to the data acquisition unit, the drive component 3, and the flow adjustment component on the gas phase recovery pipe 2, and has built-in algorithms for calculating leakage, controlling sealing force, and adjusting recovery flow. The auxiliary monitoring unit includes a flow sensor 6 for monitoring flow parameters in the gas phase recovery pipe 2 and a temperature sensor for monitoring medium temperature parameters, and its signal output terminal is connected to the control module 8. This integrated multi-functional module has a compact structure and strong synergy, facilitating retrofitting and installation on existing vehicle systems. The adjustable sealing component achieves sealing through expansion, adapting to interfaces with different leakage levels, resulting in stronger sealing adaptability. The auxiliary monitoring unit supplements flow and temperature parameters, providing more dimensional data for algorithm optimization and improving control accuracy.

[0023] The VOCs sensor is a catalytic combustion sensor with a detection range of 0-1000 mg / m³, and the VOCs sensor is located on the outside of the sealed interface 7, 5-10 cm away from the interface.

[0024] The adjustable sealing assembly includes an inner sealing ring 4 and a flexible sealing bladder 5. The inner sealing ring 4 is used to directly fit against the sealing interface 7. The flexible sealing bladder 5 is located above the inner sealing ring 4 and connected to the driving component 3. The inner sealing ring 4 is made of oil-resistant nitrile rubber or fluororubber. The driving component 3 is an air pump. The inner sealing ring 4 and the flexible sealing bladder 5 form a double seal, improving reliability. The air pump driving method provides rapid response, and the expansion pressure of the flexible sealing bladder 5 is uniform, resulting in a good sealing effect.

[0025] The control module 8 is a PLC controller and is equipped with an alarm unit. When the detected leakage exceeds the preset emergency threshold, the alarm unit will issue an audible and visual alarm and send a shutdown signal to the loading pump control system.

[0026] The flow regulation component on the gas phase recovery pipe 2 is an electric proportional regulating valve 9, which works in conjunction with the control module 8 to adjust the recovery flow rate in real time. The electric proportional regulating valve 9 has an adjustment accuracy of ±2%, which can accurately match the target recovery flow rate and avoid VOCs escape caused by flow fluctuations. Example 2

[0027] according to Figure 1 , 2 As shown, this embodiment proposes a method and device for automatically sealing gas leakage during the loading process of a bottom-loading arm, applicable to benzene loading at normal temperatures: Under normal operating conditions of 25℃ and atmospheric pressure, a DN100 bottom loading arm is used to load pure benzene into tank trucks, with the loading flow rate stably controlled at 50 m³ / h. Based on the volatility characteristics of benzene and emission standard requirements, the preset leakage threshold Q0 is 10 mg / h, and the supporting RTO tail gas treatment system has a treatment capacity of 6000 m³ / h to ensure that the volatile gases can be treated in a timely and efficient manner.

[0028] In the detection module, the VOCs sensor is a TGS2602 catalytic combustion sensor, and the pressure sensor is a PT100 model (accuracy up to ±0.1%FS), which can accurately collect parameters of the sealing part; the sealing mechanism can quickly provide stable sealing force; the control module adopts Siemens S7-1200 PLC, which has built-in leakage calculation, sealing force control and recovery flow adjustment algorithms to ensure the timeliness of logic operation and command issuance.

[0029] During loading, the VOCs concentration at the loading arm sealing interface was 45 mg / m³ before sealing, corresponding to a leakage rate of 48 mg / h, both exceeding the preset standards. After activating the automatic sealing function, the VOCs concentration rapidly decreased to 3.2 mg / m³, and the leakage rate simultaneously decreased to 3.5 mg / h, both lower than the benzene emission limit (20 mg / m³) specified in GB31571-2015 and the preset leakage threshold (10 mg / h), fully meeting the compliance requirements. The sealing response time was only 0.8 seconds, far less than the design target of 1 second, which can quickly contain the leakage. The recovery flow rate of the gas phase recovery pipe was smoothly adjusted from the initial 100 m³ / h to 109.6 m³ / h without fluctuation throughout, ensuring that all volatilized VOCs could be introduced into the RTO for treatment. Example 3

[0030] according to Figure 1 , 2 As shown, this embodiment proposes a method and device for automatically sealing gas leakage during the loading process of a bottom-loading arm, which is applied to benzene loading in low-temperature environments. At low temperatures of -5℃ and low humidity, the viscosity of benzene increases from 0.64 mPa·s at the normal 25℃ to 0.85 mPa·s due to the decrease in temperature, which may increase the risk of leakage at the sealed interface. At this time, benzene is still loaded into the truck using a DN100 loading arm. To further control leakage, the preset leakage threshold Q0 is lowered to 8 mg / h to ensure that VOCs emissions still meet environmental protection requirements at low temperatures.

[0031] To address the challenges of low-temperature environments, the material of the adjustable sealing component has been changed from conventional oil-resistant nitrile rubber to low-temperature resistant fluororubber (applicable temperature range -40℃ to 150℃) to prevent hardening and failure of the seal due to low temperatures. At the same time, based on the influence of temperature on the volatility of the medium, the correction coefficient K in the leakage calculation algorithm has been adjusted from 1.2 at the conventional 25℃ to 1.4, increasing the initial sealing force by 15% compared to conventional operating conditions, ensuring sufficient sealing pressure at low temperatures.

[0032] Before sealing, due to the change in viscosity at low temperature, the VOCs concentration at the loading arm sealing interface was 38 mg / m³, and the leakage was 39 mg / h, which is close to the leakage level under normal operating conditions. After the sealing function was activated, the VOCs concentration quickly dropped to 2.8 mg / m³, and the leakage dropped to 2.9 mg / h, both meeting the preset leakage threshold of 8 mg / h and the emission limit of 20 mg / m³. The sealing response time was 1.1 seconds, which meets the design standard of ≤1.5 seconds under low temperature conditions. Through material optimization and parameter adjustment, the wear of the seal was significantly reduced. Under normal operating conditions, the wear was 0.2 mm per month, while under low temperature conditions, the wear was only 0.15 mm per month, a 25% reduction in wear and an extension of the seal's service life.

[0033] This invention collects multi-dimensional parameters such as VOCs concentration, sealing cavity pressure difference, and gas phase recovery flow rate in real time. Combined with an algorithm that incorporates correction coefficients for media type, ambient temperature, and altitude, it can quantify and calculate leakage and determine thresholds. With closed-loop iterative adjustment in a 1-3 second cycle, it ensures that the sealing force and recovery flow rate are precisely matched to the leakage state. This improves the response speed by tens of times compared to traditional manual inspections and can control the VOCs leakage of media such as benzene to a level far below the limit. Furthermore, through the synergistic design of the dual sealing structure of the inner sealing ring 4 + flexible sealing bladder 5, catalytic combustion-type close-range VOCs sensor, and electric proportional regulating valve 9, it adapts to different wear interfaces, altitude, temperature, and media viscosity conditions, while avoiding the risk of leakage caused by the failure of a single component. This makes the VOCs recovery efficiency more stable and fully meets environmental emission requirements. Meanwhile, the PLC emergency shutdown alarm function of the control module can quickly cut off the loading process when the leakage exceeds the emergency threshold, greatly reducing the risk of explosion and personnel poisoning caused by benzene vapor accumulation; the automated operation of the device reduces the frequency of manual inspection, the double sealing structure extends the replacement cycle of the seals, and the dynamic adjustment of the recovery flow avoids energy waste, making it both practical and valuable for promotion.

[0034] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for automatically sealing gas leakage during loading of loading arms, characterized in that, Includes the following steps S1: During the loading process, two sets of core parameters are collected in real time through the detection module: VOCs concentration C at the loading arm sealing interface and pressure difference ΔP between the loading arm sealing cavity and the atmosphere. At the same time, the real-time flow rate V1 in the gas phase recovery pipe is collected. S2: The control module calls the preset algorithm to calculate the real-time leakage amount Q, compares Q with the preset leakage threshold Q0. When Q≤Q0, the current loading and gas phase recovery status is maintained. When Q>Q0, it is determined that the state needs to be sealed and S3 is executed. S3: The control module sends a command to the sealing mechanism to drive the sealing mechanism to apply a sealing force F to the sealing interface of the loading arm, and at the same time sends a command to the flow regulation component on the gas phase recovery pipe to adjust the recovery flow to the target value V. S4: Continuously collect VOCs concentration C', pressure difference ΔP', and recovery flow rate V' after plugging, recalculate the leakage Q', maintain the current plugging force and recovery flow rate when Q'≤Q0, and iteratively adjust the plugging force F and recovery flow rate V until Q'≤Q0, then return to S2 for continuous monitoring.

2. The method for automatically sealing gas leakage during loading of loading arms according to claim 1, characterized in that: In S2, the algorithm for calculating the leakage amount Q is as follows: Q = K × C × ΔP × S, Where: K is the correction factor, which is 1.2-1.5 depending on the medium type - benzene, and 1.0 when the ambient temperature is -25℃, with an increase of 0.1 correction for every 10℃ increase; C is the VOCs concentration, in mg / m³; ΔP is the pressure difference between the loading arm sealing cavity and the atmosphere, in Pa, ΔP=P1-P0, where P1 is the pressure inside the loading arm sealing cavity and P0 is the atmospheric pressure; S is the effective sealing area of ​​the loading arm sealing interface, in m², which is preset by the loading arm model.

3. The method for automatically sealing gas leakage during loading of the bottom loading arm as described in claim 2, characterized in that: In S3, the algorithm for calculating the blocking force F is as follows: F = K1 × Q × P0, Where: K1 is the force correction coefficient, set according to the type of sealing mechanism; Q is the real-time leakage calculated in S2, in mg / h; P0 is the atmospheric pressure, in Pa, used to correct the sealing force requirements at different altitudes.

4. The method for automatically sealing gas leakage during loading of a bottom-loading arm as described in claim 3, characterized in that: In S3, the algorithm for calculating the target recovery flow rate V is as follows: V = K2 × Q + V0, Where: K2 is the flow correction coefficient (unit: m³·h⁻¹ / mg·h⁻¹), set according to the RTO processing capacity; Q is the real-time leakage calculated in S2 (unit: mg / h); V0 is the basic recovery flow rate (unit: m³ / h), which is the minimum recovery flow rate when the vehicle is stable, to avoid frequent start-up and shutdown of the recovery system.

5. The method for automatically sealing gas leakage during loading of a bottom-loading arm according to claim 1, characterized in that: In S4, the iterative adjustment period is 1-3 seconds, and the change in blocking force F during each adjustment does not exceed 10% of the initial value, and the change in recovery flow rate V does not exceed 15% of the initial value.

6. An automatic gas leakage sealing device during the loading of bottom loading arms, applied to the automatic gas leakage sealing method during the loading of bottom loading arms as described in any one of claims 1-5, characterized in that: The system includes a loading arm body, a detection module, a sealing mechanism, a control module (8), and an auxiliary monitoring unit. The loading arm body has a liquid medium transport channel (1) and a gas phase recovery pipe (2). The liquid medium transport channel (1) is used to transport the medium to be loaded to the tank truck, and the gas phase recovery pipe (2) is used to export the volatile gas to the exhaust gas treatment system. The detection module includes a VOCs sensor for detecting the VOCs concentration of the sealing interface (7), a pressure sensor for detecting the pressure parameters inside the loading arm body, and a data acquisition unit for processing the sensor signals. The sealing mechanism includes an adjustable sealing component that cooperates with the sealing interface and a drive component (3) that drives the adjustable sealing component to expand and achieve sealing adjustment; the control module (8) is electrically connected to the data acquisition unit, the drive component (3) and the flow adjustment component on the gas phase recovery pipe (2), and has built-in algorithms for calculating leakage, controlling sealing force and adjusting recovery flow; the auxiliary monitoring unit includes a flow sensor (6) for monitoring flow parameters in the gas phase recovery pipe (2) and a temperature sensor for monitoring medium temperature parameters, and its signal output terminal is connected to the control module (8).

7. The automatic gas leakage sealing device during loading of the bottom loading arm as described in claim 6, characterized in that: The VOCs sensor is a catalytic combustion sensor with a detection range of 0-1000 mg / m³, and the VOCs sensor is located on the outside of the sealed interface (7), 5-10 cm away from the interface.

8. The automatic gas leakage sealing device during loading of the bottom loading arm according to claim 6, characterized in that: The adjustable sealing assembly includes an inner sealing ring (4) and a flexible sealing bladder (5). The inner sealing ring (4) is used to directly fit with the sealing interface (7). The flexible sealing bladder (5) is located above the inner sealing ring (4) and connected to the driving component (3). The inner sealing ring (4) is made of oil-resistant nitrile rubber or fluororubber. The driving component (3) is an air pump.

9. The automatic gas leakage sealing device during loading of the bottom loading arm as described in claim 6, characterized in that: The control module (8) is a PLC controller and is equipped with an alarm unit. When the leakage exceeds the preset emergency threshold, the alarm unit will issue an audible and visual alarm and send a shutdown signal to the loading pump control system.

10. The automatic gas leakage sealing device during loading of the bottom loading arm according to claim 6, characterized in that: The flow regulation component on the gas phase recovery pipe (2) is an electric proportional regulating valve (9), which works in conjunction with the control module (8) to adjust the recovery flow rate in real time.

Images