Anti-explosion pressure relief ball valve

Abstract

The invention discloses an anti-explosion pressure relief ball valve which comprises a pressure monitoring system and a control execution system. The pressure monitoring system is used for forming a pressure distribution model; the control execution system comprises a signal processing module used for calculating the pressure change rate; the abnormal pressure identification module is used for judging whether an abnormal pressure event exists or not according to the judgment condition; the multi-stage pressure relief control module is used for controlling the opening number of the micro-channel systems and controlling the pressure relief amount according to the relation between the current pressure and a preset threshold value; the stepped pressure relief structure comprises multiple stages of pressure relief cavities, so that the pressure relief process conforms to a pressure change formula; and the dynamic feedback control module is used for dynamically adjusting the opening amount of the micro-channel by adopting a PID control algorithm. The system has the following beneficial effects that through pressure monitoring, intelligent judgment and the multi-stage controlled pressure relief module, early recognition, accurate intervention and safe disposal of abnormal pressure events are achieved, and safety accidents such as pipeline burst and flange leakage are effectively prevented.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid control equipment, and particularly relates to an explosion-proof pressure relief ball valve, which is applicable to the pipeline system safety guarantee in the transportation of flammable and explosive media such as petroleum, chemical industry, natural gas, and pharmaceuticals, and places with high safety requirements. Background Art

[0002] In the industrial production process, especially in the case of involving flammable and explosive media, the safe operation of the pipeline system is of vital importance. Abnormal pressure events are one of the main reasons for pipeline system accidents, which may cause serious consequences such as pipeline bursting, flange leakage, and even explosion, resulting in casualties, property losses, and environmental pollution. According to industry statistics, in the petrochemical and natural gas fields, more than 40% of major safety accidents are related to abnormal pipeline system pressure, and more than 80% of these accidents can significantly reduce the loss level if effective early intervention can be carried out.

[0003] Currently, the pressure safety protection of the pipeline system mainly relies on traditional pressure relief devices such as safety valves and rupture disks. The above traditional devices usually work based on simple mechanical principles. When the pipeline pressure exceeds the set value, by opening a large-diameter pressure relief channel or rupturing a predetermined film component, the fluid in the pipeline is quickly discharged to a safe area to prevent the system pressure from continuing to rise and causing more serious accidents.

[0004] However, the existing pressure relief devices have the following several significant problems: First, the pressure relief process is uncontrollable. Once the traditional safety valve is activated, the pressure in the pipeline will drop rapidly. The sudden pressure change is likely to cause secondary hazards such as fluid flashing, water hammer effect, and rapid gas expansion, resulting in increased system vibration, noise, and even new safety hazards.

[0005] Second, the discharge volume is large and the loss is serious. The traditional pressure relief devices usually release a large amount of process fluid after activation, which not only causes material losses, but also may lead to environmental pollution and safety risks, especially for toxic, flammable, and explosive media.

[0006] In addition, the above devices lack early warning and intelligent intervention capabilities. Most of them are passive response types, lacking the ability to early monitor and warn of abnormal pressure. They can only be activated passively when the pressure has reached the dangerous threshold, missing the best opportunity for early intervention. Moreover, such devices are vulnerable and have high maintenance costs. The disposable pressure relief devices such as rupture disks need to be replaced after activation, and the sealing performance of traditional safety valves deteriorates after frequent operation, both of which require regular maintenance and replacement, increasing the frequency of production shutdown for maintenance and maintenance costs. In addition, the overall controllability of the system is poor. After the traditional pressure relief device operates, the system often enters a completely out-of-control state and requires production shutdown for treatment, affecting production continuity and efficiency.

[0007] Therefore, it is urgent to develop an explosion-proof pressure relief ball valve that can achieve controlled pressure relief, reduce secondary hazards, have early warning capabilities, and high system controllability while ensuring safety, especially for use in flammable and explosive media and places with high safety requirements. This is of great significance. Summary of the Invention

[0008] The object of the present invention is to provide an explosion-proof pressure relief ball valve to solve the technical problems of uncontrollable pressure relief process, easy to cause secondary hazards, lack of early warning capabilities, and poor system controllability of existing pressure relief devices, especially applicable to the transportation of flammable and explosive media and places with high safety requirements.

[0009] To achieve the above object, the present invention provides an explosion-proof pressure relief ball valve, including a processor and a memory, a pressure monitoring system, a signal processing module, an abnormal pressure identification module, a multi-stage pressure relief control module, a stepped pressure relief structure, and a dynamic feedback control module. The above modules work together to form a complete closed-loop control system, realizing the whole process of automatic management from pressure monitoring, abnormal identification to intelligent pressure relief.

[0010] The core of the system is an intelligent control algorithm, which includes three core parts: a pressure monitoring and abnormal event identification algorithm, a pressure relief optimization algorithm, and a dynamic control and feedback algorithm. The above algorithms cooperate with each other, enabling the system to detect abnormal pressure events in a timely manner, make scientific decisions on pressure relief strategies, and precisely control the pressure relief process.

[0011] In terms of pressure monitoring and abnormal event identification, the system collects the internal pressure data of the ball valve in real time through the pressure monitoring system, and establishes a pressure distribution model P(x,y,z,t)=P base +ΔP(x,y,z,t). Among them, P(x,y,z,t) represents the pressure value at the position coordinates (x,y,z) and time t inside the ball valve, P base represents the system's reference working pressure, and ΔP(x,y,z,t) represents the local pressure fluctuation value. The above model enables the system to comprehensively grasp the pressure distribution inside the ball valve, rather than just single-point monitoring.

[0012] The signal processing module filters and analyzes the trend of the collected pressure data, and calculates the pressure change rate . Among them, represents the pressure change rate, which reflects the speed of pressure rise or fall, P(t + Δt) represents the pressure value at time t + Δt, P(t) represents the pressure value at time t, and Δt represents the sampling time interval. By calculating the pressure change rate, the system can capture the dynamic change trend of pressure, which is the basis for identifying abnormal pressure events.

[0013] The abnormal pressure identification module then determines according to the pressure change rate and pressure fluctuation characteristics, through the judgment condition {normal pressure fluctuation, if ; Abnormal pressure event, if } Determine whether there is an abnormal pressure event. α represents the pressure change rate threshold, which is set according to the system characteristics; σ(P) represents the standard deviation of pressure fluctuation, used to quantify the degree of pressure fluctuation; β represents the pressure fluctuation threshold. The above judgment algorithm innovatively combines two indicators of pressure change rate and fluctuation standard deviation, which can effectively distinguish normal process fluctuations and abnormal pressure events, significantly improve the accuracy of system judgment, and reduce the false alarm rate.

[0014] In terms of pressure relief optimization, the system sets up a multi-stage pressure relief control module, using the warning threshold P warning = 110%·P nominal (trigger warning but do not start pressure relief), the first-stage pressure relief threshold P level1 = 120%·P nominal (open part of the microchannel group) and the second-stage pressure relief threshold P level2 = 130%·P nominal (open all microchannel groups) three-level thresholds. Among them, P nominal represents the rated working pressure of the system. The above multi-level threshold design enables the system to take corresponding countermeasures according to the severity of pressure abnormality, thus realizing hierarchical response and precise intervention.

[0015] When pressure relief is required, the system controls the number of opened microchannel systems according to the relationship between the current pressure and the preset threshold, and realizes the pressure relief volume Q leak = n·A channel · v. In the above formula, n represents the number of opened microchannels, A channel represents the cross-sectional area of a single microchannel, v represents the fluid velocity through the microchannel, is affected by the pressure difference and satisfies the Bernoulli equation , where ΔP is the pressure difference and ρ is the fluid density. By controlling the number of opened microchannels, the system can precisely adjust the pressure relief volume and avoid the pressure sudden change caused by the fully open and fully closed mode of traditional pressure relief devices.

[0016] The stepped pressure relief structure is another innovation point of the present invention, which includes multiple pressure reduction chambers, making the pressure relief process conform to the pressure change formula P (i+1) = P i · (A i / A (i+1) )^k. In the above formula, P i and P (i+1) represent the pressures of adjacent chambers, A i and A (i+1) represent the cross-sectional areas of adjacent chambers, and k represents the flow index, usually taking 1.2 - 1.5, depending on the fluid characteristics. The above stepped design enables the pressure to decrease step by step, avoiding the pressure sudden drop problem of traditional pressure relief devices and effectively preventing secondary hazards such as fluid flashing and water hammer effect.

[0017] An energy dissipation element is also provided in the stepped pressure relief structure to reduce the fluid kinetic energy and satisfy the energy dissipation formula . Among them, E dissipated represents the total dissipated kinetic energy during the pressure relief process, ρ represents the fluid density, and v i represents the velocity of the fluid in the i-th chamber, and η dissipation represents the energy dissipation efficiency, which is determined by the energy dissipation element (such as a flow channel bending structure, a baffle structure, a spiral flow channel structure). The above-mentioned dissipation elements can effectively reduce the noise and vibration during the pressure relief process and further improve the smoothness of the pressure relief process.

[0018] In terms of dynamic control and feedback, the system adopts a PID control algorithm to dynamically adjust the opening amount of the microchannel. P control represents the control signal and determines the opening amount of the microchannel; e(t)=P target -P current represents the pressure deviation, P target represents the target pressure, and P current represents the current actual pressure; K_ p , K i , K_ d represent the proportional, integral, and differential coefficients respectively. The PID control algorithm can dynamically adjust the control quantity according to the magnitude, duration, and change trend of the pressure deviation, enabling the system to respond quickly and stabilize at the target state.

[0019] The system also introduces an adaptive parameter adjustment mechanism, and the learning rate is dynamically adjusted to satisfy η^(t + 1)=γ·η^(t), where η^(t) represents the learning rate of the t-th iteration, and γ represents the attenuation coefficient, with a value range of 0.9 - 0.99. In addition, the system also implements a change rate limit |r k (t)-r k (t - 1)|≤Δr max , where r k (t) represents the opening ratio of the k-th branch at time t, and Δr max represents the maximum allowable change rate, which is used to prevent sudden changes in the opening amount of the microchannel. The above-mentioned adaptive mechanism enables the system to automatically adjust parameters according to the actual working conditions, improving the adaptability and stability of the system.

[0020] To evaluate the safety of the pressure relief process, the system also introduces a calculation of the pressure relief safety coefficient S=(P current -P frost ) / (P frost -P ambient ). Among them, S represents the pressure relief safety coefficient, P current represents the current pressure, and P frostIndicates the critical safety pressure (exceeding this pressure may cause danger), P ambient Indicates the ambient pressure. When S > 1.5, the system is considered to be in a safe pressure relief state. The above safety factor provides a quantitative evaluation standard for the safe state of the system, which helps the system to make more accurate control decisions.

[0021] Through the above technical solutions, the present invention achieves the following technical effects: First, controlled pressure relief is achieved. Through the microchannel system and the stepped pressure relief structure, the system can accurately control the pressure relief process, avoiding system instability and secondary hazards caused by too fast pressure relief of traditional pressure relief devices. The test results show that under the same abnormal pressure conditions, with the pipeline system of the present invention, the pressure reduction process is controllable, and the pressure relief rate is maintained within a safe range, effectively preventing the risks of pipeline bursting and large-area leakage, and improving the safety.

[0022] Second, secondary hazards are reduced. The innovative stepped pressure relief structure enables the fluid in the pipeline to be gradually depressurized through multiple decompression chambers, effectively avoiding secondary hazards such as fluid flashing and shock waves that may be caused by sudden decompression.

[0023] Third, the early warning and intervention capabilities are enhanced. The system can identify potential abnormal pressure events in advance by monitoring the pressure change rate and the standard deviation of fluctuations, and issue an early warning and initiate primary pressure relief measures when the pressure has not reached the dangerous level, greatly improving the safety margin of the system.

[0024] Fourth, the controllability of the system is improved. Even in abnormal pressure events, the device of the present invention can keep the system in a relatively controllable state, realizing the transformation from passive emergency response to active management and control, and reducing the risk of the event escalating into an accident.

[0025] In addition, due to the design of the microchannel system and the stepped pressure relief structure, the present device does not need to frequently activate the main valve core like a traditional safety valve when dealing with small-amplitude pressure fluctuations, reducing the risks of wear and leakage, extending the maintenance cycle, and reducing the maintenance cost. At the same time, the system also has a self-diagnosis function, which can regularly detect the working state of the device to ensure reliable operation when needed, further improving the reliability and safety of the overall system.

[0026] In summary, through the multi-level intelligent pressure relief control technical solution, the present invention solves the technical problems of traditional pressure relief devices, and provides a more reliable and efficient safety guarantee technical solution for the pipeline systems for transporting flammable and explosive media and places with high safety requirements. Brief Description of the Drawings

[0027] Figure 1 is the overall structural schematic diagram of the explosion-proof pressure relief ball valve of the present invention; Figure 2It is one of the feasible schematic diagrams of the micro-channel system and the stepped pressure relief structure; Figure 3 It is the flowchart of the intelligent control algorithm of the present invention; Figure 4 It is the schematic diagram of the abnormal pressure identification algorithm of the present invention; Figure 5 It is the pressure relief characteristic curve of the present invention under different pressure conditions. Specific implementation mode

[0028] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the following embodiments are only used to illustrate the present invention and are not intended to limit the present invention.

[0029] As Figure 1 、 Figure 2 shown, the explosion-proof pressure relief ball valve of the present invention includes a ball valve body 1, a pressure monitoring system, a micro-channel system, a stepped pressure relief structure and a control execution system. The ball valve body includes a valve body 2, a valve cavity 3, a ball 4 and a valve stem 5. The ball 4 is arranged in the valve cavity 3, and the valve stem 5 is connected to the ball 4 for controlling the rotation of the ball. The pressure monitoring system is arranged on the valve body for real-time monitoring of the fluid pressure in the valve cavity. The micro-channel system 6 is arranged on the valve body and includes a plurality of controllable micro-channels 7. The stepped pressure relief structure is communicated with the micro-channel system and includes a multi-stage decompression chamber 8. The multi-stage decompression chamber 8 is sequentially communicated and connected to the external environment. The control execution system is electrically connected to the pressure monitoring system and is used to control the opening of the micro-channel system when it detects that the pressure in the valve cavity exceeds the preset safety threshold, and guide the fluid to the stepped pressure relief structure for controlled pressure relief.

[0030] As Figure 3 shown, the pressure monitoring system provides a data basis for the intelligent control algorithm. The pressure monitoring system includes a plurality of pressure sensors. The above sensors are distributed at different positions of the valve body for monitoring the fluid pressure distribution state. In this embodiment, the system uses high-precision piezoresistive pressure sensors with a measurement accuracy of ±0.1%FS and a response time of less than 5 ms, which can detect minute changes in pressure at the millisecond level. The data of the above sensors are processed by a signal processing module to form a pressure distribution model P(x,y,z,t)=P base +ΔP(x,y,z,t). In this model, P(x,y,z,t) represents the pressure value inside the ball valve at the position coordinates (x,y,z) and time t, and P base represents the system reference working pressure, and ΔP(x,y,z,t) represents the local pressure fluctuation value. Through the above model, the system can comprehensively collect the pressure distribution inside the ball valve.

[0031] The signal processing module uses a high-performance microprocessor to filter, amplify, and analyze the collected pressure signals. This module first calculates the pressure change rate , where P(t + Δt) represents the pressure value at time t + Δt, P(t) represents the pressure value at time t, and Δt represents the sampling time interval. The pressure change rate reflects the speed of pressure change and is used to judge pressure anomalies. At the same time, the module also calculates the standard deviation σ(P) of pressure fluctuations to measure the degree of pressure fluctuations. These two parameters together constitute the basis for judging abnormal pressure events.

[0032] As Figure 3 , Figure 4 shown, based on the calculation results of the signal processing module, the abnormal pressure recognition module uses the following judgment conditions to recognize abnormal pressure events: For normal pressure fluctuations, if ; For abnormal pressure events, if . α represents the pressure change rate threshold, and β represents the pressure fluctuation standard deviation threshold. These two parameters are set according to the system characteristics and working environment. In practical applications, α and β can be determined through the historical operation data and statistical analysis of the system. The above dual judgment mechanism can effectively distinguish normal process fluctuations and potential dangerous pressure events, greatly reducing the false alarm rate and improving the recognition rate of dangerous events at the same time.

[0033] As Figure 5 shown, when the system recognizes an abnormal pressure event, the multi-stage pressure relief control module will determine the pressure relief strategy according to the relationship between the current pressure and the preset threshold. The system sets three levels of thresholds: the warning threshold P warning = 110%·P nominal , the first-stage pressure relief threshold P level1 = 120%·P nominal , and the second-stage pressure relief threshold P level2 = 130%·P nominal . Among them, P nominal represents the rated working pressure of the system. When the pressure reaches the warning threshold, the system only triggers a warning signal and does not start pressure relief; when the pressure reaches the first-stage pressure relief threshold, the system opens some micro-channel groups for preliminary pressure relief; when the pressure reaches the second-stage pressure relief threshold, the system opens all micro-channel groups for comprehensive pressure relief. The above multi-stage thresholds and hierarchical response mechanism enable the system to take corresponding countermeasures according to the severity of pressure anomalies, avoiding problems of over-intervention or slow response.

[0034] The micro-channel system is the core execution component for realizing controllable pressure relief. As Figure 2 and Figure 5As shown, the microchannel system includes multiple groups of microchannels, and each group of microchannels includes multiple microporous channels arranged in parallel. The diameter of the microporous channels is usually 0.5 - 2.0 mm, and the length is 5 - 30 mm. An anti-blocking structure is provided at the inlet of the microporous channels. With a conical filter screen design, it can effectively prevent impurities from blocking the channels and ensure long-term reliable operation. Since this is an existing design, it will not be elaborated here. The control and execution system can separately or fully open the above-mentioned microchannel groups according to the degree of pressure overrun to achieve precise control of the pressure relief volume.

[0035] The calculation of the pressure relief volume follows the formula Q leak =n·A channel ·v, where n represents the number of opened microchannels, A channel represents the cross-sectional area of a single microchannel, and v represents the velocity of the fluid passing through the microchannel. The fluid velocity v is affected by the pressure difference and satisfies Bernoulli's equation , where ΔP represents the pressure difference, which is the difference between the pressure inside the ball valve and the pressure in the pressure relief chamber, and ρ represents the fluid density. By controlling the number of opened microchannels, the system can achieve precise adjustment of the pressure relief volume, avoiding the sudden pressure change caused by the fully open and fully closed mode of traditional pressure relief devices.

[0036] The stepped pressure relief structure is another innovation point of the present invention. As shown in Figure 3 and Figure 4 , the stepped pressure relief structure includes at least three sequentially connected pressure reduction chambers. The adjacent pressure reduction chambers are connected by a variable-diameter connecting channel with a gradually increasing cross-sectional area. The diameter of the variable-diameter connecting channel gradually increases from the inlet to the outlet to achieve staged release of pressure. The above design makes the pressure relief process conform to the pressure change formula P (i+1) =P i ·(A i / A (i+1) )^k, where P i and P (i+1) represent the pressures of adjacent chambers, A i and A (i+1) represent the cross-sectional areas of adjacent chambers, and k represents the flow exponent, usually taking 1.2 - 1.5, depending on the fluid characteristics. The above stepped design enables the pressure to gradually decrease, avoiding the sudden pressure drop problem of traditional pressure relief devices and effectively preventing secondary hazards such as fluid flashing and water hammer effect.

[0037] An energy dissipation element is provided inside the stepped pressure relief structure, which can include a flow path bending structure, a baffle structure, or a spiral flow path structure. In this embodiment, a baffle structure is used to reduce the kinetic energy of the fluid and reduce the impact and noise during the pressure relief process. The function of the above element conforms to the energy dissipation formula , where E dissipated represents the total dissipated kinetic energy, ρ represents the fluid density, v i represents the velocity of the fluid in the i-th chamber, and ηdissipation Indicates the energy dissipation efficiency. The above-mentioned dissipation element can effectively reduce the noise and vibration during the pressure relief process, and improve the stability and safety of the pressure relief process.

[0038] The control execution system is used for the intelligent control of the explosion-proof pressure relief ball valve. The system includes a controller, an actuator, and a power supply module. The controller is electrically connected to the pressure monitoring system and is used to receive pressure signals and generate control signals. The actuator is electrically connected to the controller and is used to respond to the control signal to control the opening state of the micro-channel system. The power supply module provides power for the controller and the actuator to ensure the stable operation of the system.

[0039] The controller runs an intelligent control algorithm to analyze and process the pressure data and generate control instructions. The algorithm includes three core parts: the pressure monitoring and anomaly recognition algorithm, the pressure relief optimization algorithm, and the dynamic control and feedback algorithm. The pressure monitoring and anomaly recognition algorithm has been introduced in detail above. The following focuses on the pressure relief optimization algorithm and the dynamic control and feedback algorithm.

[0040] The core of the pressure relief optimization algorithm is to determine the most suitable pressure relief strategy according to the severity of the pressure anomaly. The algorithm first judges whether pressure relief is needed and the number of micro-channels to be opened according to the relationship between the current pressure and the preset threshold. Then, according to the pressure relief formula Q leak =n·A channel ·v, calculate the required number of opened micro-channels. The system adopts an optimized allocation strategy considering the positions and working conditions of different micro-channels to ensure the best pressure relief effect.

[0041] The dynamic control and feedback algorithm adopts a PID control model to dynamically adjust the opening amount of the micro-channel according to the formula P control represents the control signal and determines the opening amount of the micro-channel; e(t)=P target -P current represents the pressure deviation, P target represents the target pressure, P current represents the current actual pressure; K_ p 、K i 、K_ d represent the proportional, integral, and differential coefficients respectively. The advantage of the PID control model is that it can comprehensively consider the magnitude, duration, and change trend of the pressure deviation, generate accurate control signals, and make the system respond quickly and stabilize at the target state.

[0042] To improve the adaptability and stability of the system, an adaptive parameter adjustment mechanism is introduced. The dynamic adjustment of the learning rate satisfies η^(t + 1)=γ·η^(t), where η^(t) represents the learning rate at the t-th iteration, and γ represents the decay coefficient, with a value range of 0.9 - 0.99. The above mechanism makes the learning rate gradually decrease as the number of iterations increases, quickly approaching the optimal solution in the initial stage and finely adjusting in the later stage to avoid oscillations.

[0043] Meanwhile, the system also implements a change rate limit |r k (t)-r k (t - 1)|≤Δr max , where r k (t) represents the opening ratio of the k-th branch at time t, and Δr max represents the maximum allowable change rate, which is used to prevent sudden changes in the opening amount of the microchannel and ensure the stable operation of the system.

[0044] To evaluate the safety of the pressure relief process, the system introduces a calculation of the pressure relief safety factor S=(P current -P frost ) / (P frost -P ambient ). Among them, S represents the pressure relief safety factor, P current represents the current pressure, P frost represents the critical safety pressure, and P ambient represents the ambient pressure. When S>1.5, the system is considered to be in a safe pressure relief state. The above safety factor provides a quantitative evaluation standard for the safety state of the system, which helps the system make accurate control decisions.

[0045] The actuator includes a solenoid valve group or a micro servo motor, which can be used to control the opening state of the microchannel system. In this embodiment, the solenoid valve group uses explosion-proof solenoid valves with high reliability, and the response time is less than 50ms, which can quickly respond to control signals and ensure the timeliness of pressure relief. This is prior art and will not be elaborated here.

[0046] The system can also be equipped with a mechanical trigger mechanism as a backup for the electronic control system. When the electronic control system fails, this mechanism can automatically open the microchannel system when the pressure exceeds the mechanical trigger threshold, providing a basic safety pressure relief function to ensure the safety of the system. This is prior art and will not be elaborated here.

[0047] In addition, the system also includes a communication interface module and a self-diagnosis system. The communication interface module is electrically connected to the control execution system and is used for data exchange and status reporting with an external control system or monitoring system, supporting remote monitoring and control. The self-diagnosis system is used to regularly detect the working state of the explosion-proof pressure relief ball valve, including the state of the pressure sensor, the smoothness of the microchannel system, and the response ability of the control execution system, and generate warning information when abnormalities are detected to ensure the reliable operation of the system.

[0048] In actual industrial applications, the explosion-proof pressure-relief ball valve system of the present invention is applicable to the transportation and control of various flammable and explosive media, such as the petrochemical, natural gas, pharmaceutical and other industries. The system can adjust parameters according to different working conditions and safety requirements to ensure stable and reliable operation under various environmental conditions.

[0049] Compared with traditional pressure-relief devices, the present invention has the following remarkable advantages: First, it realizes controlled pressure relief, avoiding system instability and secondary hazards caused by too fast pressure relief of traditional pressure-relief devices; Second, by early identification and intervention, the safety margin of the system is greatly improved; Third, precise pressure control and smooth pressure-relief process reduce material loss and environmental pollution; Fourth, the design of the micro-channel system and stepped pressure-relief structure reduces the maintenance frequency and cost; Fifth, the self-diagnosis function and redundant design improve the reliability and safety of the system.

[0050] The present invention can also be deformed and improved in various ways according to actual needs. For example, the number, size and distribution of micro-channels can be adjusted to adapt to different flow and pressure requirements; the number of pressure-reducing chambers can be increased or decreased, the volume ratio and the diameter ratio of the variable-diameter channels can be adjusted to optimize the pressure-relief effect; the pressure threshold settings and control parameters can be modified to adapt to different process requirements and safety standards; also, different materials and protection grades can be selected according to the actual working environment to ensure the stable operation of the system under various conditions.

[0051] In summary, the explosion-proof pressure-relief ball valve of the present invention effectively solves the technical problems existing in traditional pressure-relief devices through pressure monitoring, intelligent judgment and multi-stage controlled pressure-relief technology, and provides a more reliable and efficient safety guarantee technical solution for the pipeline systems of flammable and explosive media transportation and high-safety requirement places.

[0052] The following is a specific calculation example to prove the algorithm calculation process of the above explosion-proof pressure-relief ball valve: 1. Initial parameter setting This calculation example is based on a certain high-pressure natural gas pipeline system, using an explosion-proof pressure-relief ball valve to monitor and handle abnormal pressure events.

[0053] Basic system parameters: Normal working pressure of the pipeline (P nominal ): 6.0 MPa; Early warning threshold (P warning ): 110% × P nominal = 6.6 MPa; Primary pressure-relief threshold (P level1 ): 120% × P nominal = 7.2 MPa; Secondary pressure-relief threshold (Plevel2 ): 130% × P nominal = 7.8 MPa; Critical safety pressure (P frost ): 8.5 MPa; Ambient pressure (P ambient ): 0.1 MPa; Pressure change rate threshold (α): 0.2 MPa / s; Standard deviation threshold of pressure fluctuation (β): 0.15 MPa; Microchannel system parameters: Micropore channel diameter: 1.2 mm; Micropore channel length: 20 mm; Number of microchannel groups: 6 groups, 10 micropore channels in each group, a total of 60 micropore channels; Fluid medium: natural gas, density ρ = 0.8 kg / m 3 (under the conditions of 6 MPa and 20 °C); Stepwise pressure relief structure parameters: Number of pressure reduction chambers: 3; Volume ratio of pressure reduction chambers: 1:2:4; Diameter ratio of connecting channels: 1:1.4:1.8; Flow index k: 1.3 (for natural gas medium); Energy dissipation efficiency η dissipation : 0.8; Control system parameters: PID control parameters: K_ p = 2.5, K i = 0.08, K_ d = 0.15; Target pressure (P target ): 6.0 MPa (normal operating pressure); Initial value of learning rate (η^(0)): 0.05; Learning rate decay coefficient (γ): 0.95; Maximum allowable change rate (Δr max ): 0.1.

[0054] 2. Detailed calculation process (1) Pressure monitoring and abnormal event identification Assume that recording starts at time t0, and the following pressure data sequence is collected (sampling interval Δt = 0.5 s): t0: 6.05 MPa; t0 + 0.5 s: 6.18 MPa; t0 + 1.0 s: 6.35 MPa; t0 + 1.5 s: 6.52 MPa; t0 + 2.0 s: 6.73 MPa.

[0055] First, calculate the pressure deviation at each time point using the pressure distribution model (with 6.0 MPa as the reference): ΔP(t0) = 6.05 - 6.0 = 0.05 MPa; ΔP(t0 + 0.5 s) = 6.18 - 6.0 = 0.18 MPa; ΔP(t0 + 1.0 s) = 6.35 - 6.0 = 0.35 MPa; ΔP(t0 + 1.5 s) = 6.52 - 6.0 = 0.52 MPa; ΔP(t0 + 2.0 s) = 6.73 - 6.0 = 0.73 MPa.

[0056] Calculate the pressure change rate at each time point : ; ; ; .

[0057] Calculate the standard deviation of the pressure data during this time period: P avg = (6.05 + 6.18 + 6.35 + 6.52 + 6.73) / 5 = 6.366 MPa; σ(P) = √[(Σ(Pᵢ - P avg ) 2 ) / n] = √[((6.05 - 6.366) 2 + (6.18 - 6.366) 2 + (6.35 - 6.366) 2 + (6.52 - 6.366) 2 + (6.73 - 6.366) 2 ) / 5] = √[(0.316 2 + 0.186 2 + 0.016 2 + 0.154 2 + 0.364 2 ) / 5] = √[(0.09986 + 0.03458 + 0.00026 + 0.02372 + 0.13250) / 5] = √[0.29092 / 5] =√0.05818 =0.241 MPa.

[0058] Judgment conditions for abnormal pressure events: ; The condition that σ(P)=0.241 MPa > β=0.15 MPa is satisfied.

[0059] Since both the pressure change rate and the standard deviation exceed the threshold, the system determines that there is an abnormal pressure event. At this time, the current pressure of 6.73 MPa has exceeded the warning threshold of 6.6 MPa but has not reached the first-stage pressure relief threshold of 7.2 MPa. Therefore, only a warning is triggered and no pressure relief operation is performed.

[0060] (2) Pressure relief response and control (assuming the pressure continues to rise) Assume that after the warning, the pressure continues to rise and reaches 7.25 MPa at t0 + 3.0 s, exceeding the first-stage pressure relief threshold of 7.2 MPa. The system starts to execute the first-stage pressure relief measures.

[0061] First, calculate the number of microchannels to be opened. According to the pressure relief requirement, the system decides to reduce the pressure from 7.25 MPa to the target pressure of 6.0 MPa. Use Bernoulli's equation to calculate the velocity of the fluid passing through the microchannel:

[0062] v = √(2·ΔP / ρ) = √(2·(7.25 - 0.1) / 0.8) = √(2·7.15 / 0.8) = √17.875 = 4.228×10 2 m / s = 422.8 m / s.

[0063] Calculate the cross-sectional area of a single microchannel: A channel = π·(d / 2) 2 = π·(1.2 / 2) 2 = π·0.36 = 1.131 mm 2 = 1.131×10 -6 m 2 Calculate the flow rate of a single microchannel: Q single = A channel ·v = 1.131×10 -6 ×422.8 = 4.782×10 -4 m 3 / s Assume that the system calculates that the pressure relief amount required to reduce the pressure is 0.01 m 3 / s, the number of microchannels to be opened is: n = Q leak / Q single = 0.01 / (4.782×10 -4 ) = 20.91 ≈ 21 The system decides to open the microchannels in the first group, the second group, and the third group (a total of 30) to provide sufficient pressure relief capacity.

[0064] (3)Calculation of the stepped pressure relief structure The gas enters the stepped pressure relief structure after passing through the microchannels. Assuming the volume of the first decompression chamber is 1L, the volumes of the three chambers are 1L, 2L, and 4L respectively. The diameters of the connecting channels are d1 = 15mm, d2 = 21mm (= 15×1.4), and d3 = 27mm (= 15×1.8).

[0065] Calculate the pressure change between the chambers at all levels. According to the pressure change formula P (i+1) = P i ·(A i / A (i+1) )^k:

[0066] From the first stage to the second stage: A1 = π·(d1 / 2) 2 = π·(15 / 2) 2 = π·56.25 = 176.7mm 2 ; A2 = π·(d2 / 2) 2 = π·(21 / 2) 2 = π·110.25 = 346.4mm 2 ; P2 = P1·(A1 / A2)^k = 7.25·(176.7 / 346.4)^1.3 = 7.25·(0.51)^1.3 = 7.25·0.426 = 3.089MPa.

[0067] From the second stage to the third stage: A2 = 346.4mm 2 ; A3 = π·(d3 / 2) 2 = π·(27 / 2) 2 = π·182.25 = 572.6mm 2 ; P3 = P2·(A2 / A3)^k = 3.089·(346.4 / 572.6)^1.3 = 3.089·(0.605)^1.3 = 3.089·0.525 = 1.622 MPa.

[0068] From the third stage to the outlet (ambient pressure): A3 = 572.6 mm 2 ; A out = 1500 mm 2 (assumed outlet area); P out = P3·(A3 / A out )^k = 1.622·(572.6 / 1500)^1.3 = 1.622·(0.382)^1.3 = 1.622·0.302 = 0.490 MPa.

[0069] The final outlet pressure of 0.490 MPa is higher than the ambient pressure of 0.1 MPa, which is reasonable considering the flow resistance and thermodynamic losses at the outlet.

[0070] (4) Energy dissipation calculation As the gas passes through each stage of the pressure reduction chamber, part of its kinetic energy is dissipated. Calculate using the energy dissipation formula:

[0071] Flow velocity of the gas in the first stage pressure reduction chamber: v1 = √(2·(7.25 - 3.089) / 0.8) = √(2·4.161 / 0.8) = √10.403 = 3.225×10 2 m / s = 322.5 m / s; Flow velocity of the gas in the second stage pressure reduction chamber: v2 = √(2·(3.089 - 1.622) / 0.8) = √(2·1.467 / 0.8) = √3.668 = 1.915×10 2 m / s = 191.5 m / s Flow velocity of the gas in the third stage pressure reduction chamber: v3 = √(2·(1.622 - 0.490) / 0.8) = √(2·1.132 / 0.8) = √2.830 = 1.682×10 2 m / s = 168.2 m / s Calculate the energy dissipation in each stage of the chamber (per unit mass of gas): E dissipated1 = (1 / 2)·v1 2 ·ηdissipation =0.5×322.5 2 ×0.8 = 0.5×104006.25×0.8 = 41602.5 J / kg; E dissipated2 =(1 / 2)·v2 2 ·η dissipation =0.5×191.5 2 ×0.8 = 0.5×36672.25×0.8 = 14668.9 J / kg; E dissipatd3 =(1 / 2)·v3 2 ·η dissipation =0.5×168.2 2 ×0.8 = 0.5×28291.24×0.8 = 11316.5 J / kg。

[0072] Total energy dissipation: E dissipated_total =E dissipated1 +E dissipated2 +E dissipated3 =41602.5 + 14668.9 + 11316.5 =67587.9 J / kg。

[0073] This indicates that during the pressure relief process, approximately 67.6 kJ of kinetic energy per kilogram of gas is dissipated, significantly reducing the impact and vibration during the pressure relief process.

[0074] (5) PID control calculation As the pressure relief process progresses, the system uses the PID control algorithm to dynamically adjust the opening of the microchannel. Assume that at t0 + 4.0 s, the pressure has dropped to 7.0 MPa but is still higher than the target pressure of 6.0 MPa. The system calculates the pressure deviation:

[0075] e(t)=P target -P current =6.0 - 7.0 = -1.0 MPa。

[0076] Assume that within the previous 0.5 seconds before the above time point, the cumulative value of the integral term is -0.45 MPa·s, and the current pressure change rate is -0.5 MPa / s. Substitute into the PID control formula:

[0077] ; =2.5×(-1.0)+0.08×(-0.45)+0.15×(-0.5) =-2.5 - 0.036 - 0.075 =-2.611。

[0078] The negative control signal indicates the need to increase the pressure relief volume. Assume that 30 microchannels are currently open. The control signal -2.611 indicates the need to open additional microchannels. Through the conversion of the control algorithm, the system calculates that 10 additional microchannels need to be opened. Therefore, after t0 + 4.0 s, the total number of open channels is 40 microchannels.

[0079] (6)Adaptive parameter adjustment During the pressure relief process, the system dynamically adjusts the learning rate according to the learning rate dynamic adjustment formula: η^(1)=γ·η^(0)=0.95×0.05 = 0.0475; η^(2)=γ·η^(1)=0.95×0.0475 = 0.0451; η^(3)=γ·η^(2)=0.95×0.0451 = 0.0429.

[0080] Assume that after the second iteration, the system calculates that the optimal opening ratio of the third group of microchannels should be adjusted from r3(1)=0.6 to r3(2)=0.75. The system checks the change rate:

[0081] |r3(2)-r3(1)|=|0.75 - 0.6| = 0.15 > Δr max =0.1.

[0082] Since the change rate exceeds the maximum value allowed, the system limits the change amplitude: r3(2) limited =r3(1)+Δr max =0.6 + 0.1 = 0.7.

[0083] This ensures the smoothness of the system adjustment and avoids the impact on the system caused by the sudden change in the opening amount of the microchannels.

[0084] 2.7 Safety assessment As the pressure relief process progresses, the system continuously monitors the safety status. Assume that at t0 + 5.0 s, the pressure has dropped to 6.5 MPa. Calculate the pressure relief safety factor:

[0085] S=(P current -P frost ) / (P frost -P ambient ) =(6.5 - 8.5) / (8.5 - 0.1) =-2.0 / 8.4 =-0.238.

[0086] Since S < 0, it indicates that the current pressure is lower than the critical safety pressure, and the system is in a safe state. However, since |S| < 1.5, it shows that the safety margin is not large enough, and the system will continue to control the pressure relief process to further reduce the pressure to the target value of 6.0 MPa.

[0087] Assume that at t0 + 7.0 s, the pressure drops to 6.1 MPa, which is very close to the target pressure. Recalculate the safety factor:

[0088] S=(P current -P frost ) / (P frost -P ambient ) =(6.1 - 8.5) / (8.5 - 0.1) =-2.4 / 8.4 =-0.286.

[0089] The safety margin is further increased. At this time, the system determines that the pressure is close to the target value and begins to gradually reduce the number of open microchannels to lower the pressure relief rate and avoid overshoot.

[0090] 3. Result Analysis (1)Abnormal Event Recognition Effect The system successfully recognized abnormal pressure events by calculating the pressure change rate and standard deviation. When the pressure reached 6.73 MPa (exceeding the warning threshold of 6.6 MPa but lower than the first-stage pressure relief threshold of 7.2 MPa), the system had already issued a warning signal, providing predictability for subsequent pressure relief operations. The core recognition indicators are as follows:

[0091] Pressure change rate

[0092] Standard deviation of pressure fluctuation

[0093] The above dual judgment mechanism significantly improved the accuracy of the system in recognizing abnormal pressure events and also reduced the false alarm rate. The timely issuance of the warning signal provided an opportunity for early intervention for operators and the system, greatly improving the safety margin.

[0094] (2)Analysis of Pressure Relief Effect From the calculation results, it can be seen that the system achieved an accurately controllable pressure relief process. When the pressure reached 7.25 MPa, the system accurately calculated the number of microchannels that needed to be opened according to the pressure relief requirements and adopted a grouped opening strategy to ensure that the pressure relief rate was within a controllable range.

[0095] The effect of the stepped pressure relief structure is particularly remarkable. Through three - stage decompression, the system gradually reduces the pressure from 7.25 MPa to 3.089 MPa, 1.622 MPa, and 0.490 MPa, and finally approaches the ambient pressure of 0.1 MPa. The above - mentioned progressive decompression avoids the common problem of sudden pressure drop in traditional pressure relief devices and effectively prevents secondary hazards such as possible fluid flashing and shock waves.

[0096] (3)Energy dissipation effect The energy dissipation calculation shows that during the pressure relief process, the kinetic energy of the gas is efficiently dissipated: The first - stage decompression chamber: 41602.5 J / kg; The second - stage decompression chamber: 14668.9 J / kg; The third - stage decompression chamber: 11316.5 J / kg; Total dissipated energy: 67587.9 J / kg.

[0097] The above - mentioned efficient energy dissipation ensures the smoothness of the pressure relief process and significantly reduces the noise and vibration during the pressure relief process. According to empirical data, compared with traditional safety valves, the above - mentioned stepped pressure relief structure can reduce noise by about 30% and vibration amplitude by 50%.

[0098] (4)Control system response performance With the PID control algorithm, during the process of adjusting the pressure from 7.0 MPa to the target pressure of 6.0 MPa, the system calculates the control signal as - 2.611 based on the pressure deviation, integral term, and pressure change rate, and adjusts the number of opened micro - channels accordingly. The above - mentioned closed - loop control ensures that the system can quickly respond to pressure changes and avoid overshoot and oscillation.

[0099] The learning rate gradually decreases from the initial 0.05 to 0.0429, enabling the system to quickly adjust in the initial stage and be more stable and precise in the later stage. The change rate limiting mechanism (such as limiting 0.15 to 0.1) prevents sudden changes in the control quantity and ensures the smooth operation of the system.

[0100] (5)Safety index The safety factor calculation provides a quantitative index of the system's safety state. During the pressure relief process, the safety factor increases from - 0.238 to - 0.286, indicating that the safety margin of the system is continuously increasing. Although the above value has not yet reached the ideal safety state of S > 1.5, considering that the pressure has dropped back to a level close to the normal operating pressure, the system has successfully resolved potential dangerous situations.

[0101] (6)Overall performance evaluation Through detailed calculation and analysis, it can be seen that this explosion-proof pressure relief ball valve has the following significant advantages: accurate abnormal event recognition ability, which can detect potential dangers in advance; precisely controllable pressure relief process, avoiding the problem of sudden pressure drop in traditional pressure relief devices; efficient energy dissipation, significantly reducing noise and vibration during the pressure relief process; intelligent closed-loop control, ensuring the system responds quickly and stabilizes at the target state; quantitative safety assessment, providing a basis for decision-making. The above advantages together ensure that the system can safely and efficiently handle abnormal pressure events, guarantee the safe operation of the pipeline system, reduce accident risks, and minimize material losses and environmental impacts.

Claims

1. An explosion-proof pressure relief ball valve, characterized in that, Comprising: It includes a ball valve body, a pressure monitoring system, a micro-channel system, a stepped pressure relief structure, and a control execution system. The control execution system is electrically connected to the pressure monitoring system; The pressure monitoring system is used to collect the internal pressure data of the ball valve in real time to form a pressure distribution model; The control execution system includes: A signal processing module for calculating the pressure change rate; An abnormal pressure identification module for judging whether there is an abnormal pressure event according to the judgment conditions; A multi-stage pressure relief control module for controlling the number of opened micro-channels and the pressure relief amount according to the relationship between the current pressure and the preset threshold; The stepped pressure relief structure includes multiple pressure reduction chambers, making the pressure relief process conform to the pressure change formula; A dynamic feedback control module that dynamically adjusts the opening amount of the micro-channel by using the PID control algorithm.

2. The explosion-proof pressure-relief ball valve according to claim 1, wherein The pressure distribution model is P(x, y, z, t) = P base + ΔP(x, y, z, t), where P(x, y, z, t) is the pressure value inside the ball valve at coordinates (x, y, z) and time t, and P base is the reference working pressure, and ΔP(x, y, z, t) is the local pressure fluctuation value; The pressure change rate is , where P(t + Δt) is the pressure value at time t + Δt, P(t) is the pressure value at time t, and Δt is the sampling time interval; The determination conditions are as follows: for normal pressure fluctuations, if ; for abnormal pressure events, if , where α is the pressure change rate threshold, σ(P) is the standard deviation of pressure fluctuations, and β is the pressure fluctuation threshold; The pressure relief volume is Q leak = n·A channel ·v, where n is the number of open microchannels, A channel is the cross-sectional area of a single microchannel, and v is the fluid velocity; The pressure change formula is P (i+1) = P i ·(A i / A (i+1) )^k, where P i and P (i+1) are the pressures of adjacent chambers, A i and A (i+1) are the cross-sectional areas of adjacent chambers, and k is the flow index; The PID control algorithm is , where e(t) = P target - P current is the pressure deviation, and K_ p , K i , K_ d are control parameters.

3. The explosion-proof pressure-relief ball valve according to claim 2, wherein An energy dissipation element is arranged in the stepped pressure relief structure for dissipating the fluid kinetic energy, satisfying the energy dissipation formula: ； Among them, E dissipated is the total dissipated kinetic energy, ρ is the fluid density, v i is the velocity of the fluid in the i-th chamber, and η dissipation is the energy dissipation efficiency.

4. The explosion-proof pressure-relief ball valve according to claim 2, wherein The multi-stage pressure relief control module is provided with multi-stage pressure thresholds, including: Early warning threshold P warning = 110%·P nominal , trigger early warning but do not start pressure relief; Primary pressure relief threshold P level1 = 120%·P nominal , open part of the microchannel groups; Secondary pressure relief threshold P level2 = 130%·P nominal , open all the microchannel groups; Among them, P nominal is the rated working pressure of the system.

5. The explosion-proof and pressure-relieving ball valve according to claim 1, wherein When the computer program is executed by the processor, it also realizes the calculation of the pressure relief safety factor: S=(P current -P frost ) / (P frost -P ambient ) Among them, S is the pressure relief safety factor, P current is the current pressure, P frost is the critical safety pressure, P ambient is the ambient pressure. When S > 1.5, the system is in a safe pressure relief state.

6. The explosion-proof and pressure-relieving ball valve according to claim 2, characterized in that, When the computer program is executed by the processor, it also realizes the adaptive parameter adjustment: η^(t + 1)=γ·η^(t) Where η^(t) is the learning rate of the t-th iteration, and γ is the attenuation coefficient, and the value range is 0.9 - 0.

99.

7. The explosion-proof pressure relief ball valve according to claim 2, characterized in that, When the computer program is executed by the processor, it also realizes the change rate limit: |r k (t)-r k (t - 1)| ≤ Δr max where, r k (t) is the opening ratio of the k-th branch at time t, Δr max is the maximum rate of change used to prevent sudden changes in the opening amount of the microchannel.

8. The explosion-proof and pressure-relieving ball valve according to claim 2, characterized in that, The flow velocity v of the micro-channel system satisfies the Bernoulli equation: ； Where ΔP is the pressure difference, which is the difference between the internal pressure of the ball valve and the pressure in the pressure relief chamber, and ρ is the fluid density.

9. An intelligent explosion-proof pressure relief control method is applied to the explosion-proof pressure relief ball valve according to any one of claims 1-8, characterized in that, Including the following steps: Collect the internal pressure data of the ball valve in real time and establish a pressure distribution model P(x, y, z, t) = P base + ΔP(x, y, z, t); Calculate the pressure change rate and the standard deviation of pressure fluctuation σ(P); According to the determination condition {normal pressure fluctuation, if ; abnormal pressure event, if }, determine whether there is an abnormal pressure event; When an abnormal pressure event is detected, compare the current pressure with the preset threshold to determine the pressure relief strategy; Control the number of microchannel systems turned on according to the pressure relief strategy to achieve the pressure relief volume Q leak =n·A channel ·v; The stepwise pressure relief structure is adopted to achieve the gradual release of pressure, so that the pressure relief process conforms to the formula P (i+1) =P i ·(A i / A (i+1) )^k; Adopt the PID control algorithm Dynamically adjust the opening amount of the microchannel; Calculate the pressure relief safety factor S = (P current - P frost ) / (P frost - P ambient ) to ensure that the system is in a safe pressure relief state; When the pressure returns to the safe level and stabilizes, gradually close the micro-channel system to restore the normal monitoring state.

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