A testing device and testing method for spring-loaded safety valves

Abstract

This invention relates to the field of valve testing technology, specifically a testing device and method for spring-loaded safety valves. The testing device includes a pressure-stabilizing pipeline system and a safety valve system. The pressure-stabilizing pipeline system provides the testing medium to the safety valve. The safety valve system includes an action performance testing component and a reseating impact force detection component. After assembling the safety valve and the testing device, the following steps are performed: First, the pressure in the test container reaches a preset pressure. Second, the inlet pressure, inlet temperature, outlet temperature, valve stem displacement, and mass flow rate are collected during the opening and discharging processes of the safety valve, and the accuracy of the opening and the stability of the discharging process are analyzed. Third, the inlet pressure, valve stem displacement, valve stem acceleration, and instantaneous reseating impact force of the safety valve are collected during the reseating process. Fourth, the force on the valve seat during the reseating process is analyzed and obtained, thus achieving the testing of the impact characteristics of the safety valve.

Description

Technical Field

[0001] This invention relates to the field of valve testing technology, and in particular to a testing device and method for spring-loaded safety valves. Background Technology

[0002] Safety valves are crucial safety accessories for pressure-bearing equipment such as boilers, pressure vessels, and pressure pipelines, and are widely used in aerospace, nuclear power, thermal power, and petrochemical industries. A safety valve is a purely mechanical, automatic pressure relief device driven by inlet static pressure. Its working principle is as follows: when the pressure inside the container exceeds a certain value, the valve automatically opens due to the pressure of the medium itself, rapidly discharging a certain amount of medium. When the pressure inside the container drops to the allowable value, the valve automatically closes, ensuring that the pressure inside the container remains below the upper limit of the allowable pressure, automatically preventing accidents that may occur due to overpressure. As the last line of defense against overpressure in equipment, the reliability of safety valves is of paramount importance to the stable operation of the equipment.

[0003] The impact characteristics of a safety valve refer to the impact generated during the valve's reseating process and its influencing factors. In practical applications, the impact generated during reseating can lead to problems such as damage to the sealing surface, system pressure fluctuations, valve and pipeline vibration, and noise, severely impacting the safety valve's reliability. Conventional design methods often rely on engineering experience to estimate the impact, which deviates significantly from actual operating conditions. This lack of understanding of the safety valve's reseating impact characteristics and the absence of reliable impact test data result in a lack of theoretical data support for related design work, affecting the overall reliability of the safety valve.

[0004] Currently, there is a lack of test methods for analyzing the impact characteristics of safety valves. Conventional impact testing methods involve directly mounting sensors on the impact surface. However, since the impact surface of a safety valve is also its sealing surface, directly mounting sensors on the sealing surface will severely affect the sealing performance of the safety valve, causing it to fail to open normally. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned shortcomings of the prior art and provide a testing device and testing method for spring-loaded safety valves, which can realize the testing of the impact characteristics of safety valves.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is: a testing device for a spring-loaded safety valve, used to test the safety valve, the safety valve including a valve seat, valve body, valve disc, bushing, retaining ring, guide sleeve, valve stem, valve cover, lower spring seat, spring, upper spring seat and adjusting screw; the testing device includes a pressure stabilizing pipeline system and a safety valve system;

[0007] The pressure-stabilizing pipeline system is used to provide the medium required for testing the safety valve; the pressure-stabilizing pipeline system includes a gas storage tank, an electric diaphragm pressure regulating valve, a front electric shut-off valve, a mass flow sensor, a test container, and a rear electric shut-off valve; in the direction of airflow, the gas storage tank, electric diaphragm pressure regulating valve, front electric shut-off valve, mass flow sensor, test container, and rear electric shut-off valve are arranged sequentially and connected; the output end of the rear electric shut-off valve is connected to the input port of the safety valve;

[0008] The safety valve system includes an action performance testing component and a reseating impact force detection component;

[0009] The motion performance testing component includes

[0010] An inlet pressure sensor is used to detect the pressure at the inlet of the safety valve;

[0011] An inlet temperature sensor is used to detect the temperature at the inlet of the safety valve.

[0012] An outlet temperature sensor is used to detect the temperature at the outlet of the safety valve.

[0013] Laser displacement sensor, used to detect the displacement of valve stem;

[0014] And an acceleration sensor, used to detect the acceleration when the valve stem moves;

[0015] The reseating impact force detection assembly includes an impact force sensor, a preload bolt, a hammer head, and a steel ball. During testing, the impact force sensor is mounted on the preload bolt, one end of which is fixedly connected to the valve stem, and the other end is fixedly connected to the hammer head. The impact force sensor is located between the hammer head and the valve stem, and a preload force is applied to the impact force sensor through the hammer head. A ball socket is provided on the lower side of the hammer head, and the steel ball is located between the ball socket and the valve disc.

[0016] In the aforementioned test apparatus for a spring-loaded safety valve, the pressure stabilizing pipeline system further includes a vent valve, which is connected to the output end of the rear electric shut-off valve for venting.

[0017] In the aforementioned testing device for a spring-loaded safety valve, the pressure-stabilizing pipeline system further includes a shut-off valve located on the pipeline between the gas storage tank and the test container, for manually controlling the opening and closing of the pipeline.

[0018] In the aforementioned test device for a spring-loaded safety valve, the acceleration sensor is magnetically mounted on the lower end face of the lower spring seat.

[0019] In the aforementioned test apparatus for a spring-loaded safety valve, an inlet pressure sensor and an inlet temperature sensor are arranged at 180° intervals in the circumferential direction of the valve body inlet; and in the inlet airflow direction of the valve body inlet, the inlet pressure sensor and the inlet temperature sensor are arranged at intervals.

[0020] In the aforementioned test apparatus for spring-loaded safety valves, the preload applied by the hammer to the impact force sensor should be no less than 1 / 4 of the test range of the impact force sensor.

[0021] Using the above-described test method for a test device for spring-loaded safety valves, after assembling the safety valve and the test device, the following steps are performed sequentially:

[0022] Step 1: Bring the pressure in the test container to the preset pressure;

[0023] Step 2: Open the safety valve and release the gas;

[0024] Control the gas outflow from the test container; gradually open the safety valve and discharge the medium until it reaches full opening height, and enter the stable discharge stage; collect the inlet pressure, inlet temperature, outlet temperature, valve stem displacement and mass flow rate during the opening and discharge process of the safety valve during the test, and analyze and judge whether the opening of the safety valve is accurate and whether the discharge process is stable;

[0025] Step 3: Reseating the safety valve;

[0026] As the safety valve releases air, the pressure inside the test container continuously decreases, and the safety valve begins to reseat until it re-seales. The inlet pressure, valve stem displacement, valve stem acceleration, and instantaneous impact force during the reseatment process are collected.

[0027] Step 4: Analyze and obtain the force on the valve seat during the safety valve reseating process.

[0028] In the above test method, the fourth step of analyzing and obtaining the force on the valve seat during the safety valve reseating process includes the following steps:

[0029] Calculate the total mass m of the moving parts 总 :

[0030]

[0031] In the formula:

[0032] m 阀杆 It is the mass of the valve stem;

[0033] m 阀瓣 It is the quality of the valve disc;

[0034] m 传感器 It is the total mass of the impact sensor, preload bolts, and hammer.

[0035] m 下弹簧座 It is the mass of the lower spring seat;

[0036] m 弹簧 It is the mass of the spring;

[0037] The force F exerted by the medium on the valve disc is calculated. 介质 :

[0038] F 介质 =P·S 密封

[0039] In the formula:

[0040] P is the inlet pressure of the safety valve;

[0041] S 密封 The sealing area of ​​the safety valve;

[0042] Calculate and obtain partial impact force F 部冲 :

[0043] F 部冲 =F 实测 -F 弹簧

[0044] In the formula:

[0045] F 实测 The resultant force measured by the impact force sensor;

[0046] F 弹簧 This refers to the spring preload.

[0047] Real Impact F 总冲 :

[0048]

[0049] In the formula:

[0050] m 总 It is the total mass of the moving parts;

[0051] m 阀瓣 It is the quality of the valve disc;

[0052] m 传感器 It is the total mass of the impact sensor, preload bolts, and hammer.

[0053] F 部冲 It is part of the impact force;

[0054] The actual resultant force F on the valve seat 座 :

[0055] F 座 =F 总冲 +F 弹簧 -F介质 +m 总 g

[0056] In the formula:

[0057] F 总冲 It's a real impact;

[0058] F 弹簧 This refers to the spring preload.

[0059] F 介质 It is the force exerted by the medium on the valve disc;

[0060] m 总 It is the total mass of the moving parts.

[0061] In the above testing method, the first step includes the following steps:

[0062] Start the system and set the test pressure for the safety valve to be tested;

[0063] Open the upstream electric shut-off valve of the test container and close the downstream electric shut-off valve to supply gas into the test container from the gas storage tank.

[0064] The opening degree of the electric shut-off valve is controlled to reach the maximum, and the gas pressure inside the test container is determined by the pressure sensor of the test container.

[0065] When the pressure inside the test container reaches 80% of the test set pressure, the opening of the electric shut-off valve is reduced, thereby slowing down the air intake of the test container and reducing pressure fluctuations.

[0066] When the air pressure inside the test container reaches the set pressure, the electric shut-off valve is closed, and the pressure inside the pressure vessel stabilizes at the set pressure.

[0067] In the second step of the above testing method, the inlet pressure, inlet temperature, outlet temperature, valve stem displacement curve, and mass flow rate during the opening and discharge process of the safety valve are collected by the inlet pressure sensor, inlet temperature sensor, outlet temperature sensor, laser displacement sensor, acceleration sensor, and mass flow sensor, respectively.

[0068] Compared with the prior art, the present invention has the following advantages:

[0069] 1) The impact testing device and testing method designed in this invention adopt a rigid connection of valve stem, impact force sensor and hammer head, and a limiting method of valve disc, bushing and ferrule, to ensure that the action performance and sealing performance of safety valve are not affected during the test, reduce the impact of instantaneous vibration of reseating on impact force sensor, ensure accurate sensor measurement and reliable operation, and realize accurate measurement of the reseating impact force of safety valve.

[0070] 2) This invention directly installs the impact sensor inside the valve disc. This installation method ensures the operating performance and sealing performance of the safety valve, solves problems such as reliable sensor installation, signal transmission, and accurate measurement, and realizes the testing of the impact characteristics of the safety valve.

[0071] 3) This invention uses pressure sensors, temperature sensors, mass flow sensors, acceleration sensors, displacement sensors, and impact force sensors to achieve synchronous real-time acquisition of six physical quantities, including inlet pressure, inlet and outlet temperatures, discharge volume, displacement of moving parts, acceleration of moving parts, and reseating impact force, throughout the entire process of opening, discharging, and reseating of the safety valve.

[0072] 4) This invention can effectively test the impact characteristics of a safety valve by monitoring its inlet pressure, inlet and outlet temperatures, valve stem displacement, valve stem acceleration, reseating impact force, and discharge rate.

[0073] 5) Based on experimental principles, this invention uses mathematical theory to deduce the actual impact force of the safety valve and the resultant force on the valve seat, providing theoretical and data support for the design of the safety valve sealing surface. Attached Figure Description

[0074] Figure 1 This is a schematic diagram of the air circuit structure of a safety valve testing device;

[0075] Figure 2 This is a schematic diagram of the safety valve testing device.

[0076] Figure 3 This is a schematic diagram of the installation structure of the displacement sensor;

[0077] Figure 4 This is a schematic diagram of the structure of the mounting bracket on the displacement sensor;

[0078] Figure 5 This is a schematic diagram of the upper end plate of the lower fixed bracket for the displacement sensor.

[0079] Figure 6 This is a schematic diagram of the impact sensor installation method;

[0080] Figure 7 This is a block diagram of the data acquisition system.

[0081] Figure 8 This is a signal flow diagram of the acquisition system;

[0082] Figure 9 This is a force analysis diagram of the safety valve during the reseating process.

[0083] In the picture:

[0084] 1-Gas source; 2-Gas tank; 3-Stop valve; 4-Electric diaphragm pressure regulating valve; 5-Front electric stop valve; 6-Mass flow sensor; 7-Test container; 8-Rear electric stop valve; 9-Safety valve system; 10-Vent valve; 11-Valve seat; 12-Valve body; 13-Valve disc; 14-Bushing; 15-Snap ring; 16-Guide sleeve; 17-Valve stem; 18-Valve cover; 19-Lower spring seat; 20-Spring; 21-Upper spring seat; 22-Adjusting screw; 23-Inlet pressure Sensors; 24-Outlet temperature sensor; 25-Acceleration sensor; 26-Laser displacement sensor; 27-Upper mounting bracket for displacement sensor; 28-Lower mounting bracket for displacement sensor; 29-Laser displacement detection block; 30-Set screw; 31-Connecting hole; 32-Upper mounting hole; 33-Lower mounting hole; 34-Light transmission hole; 35-Impact sensor; 36-Preload bolt; 37-Hammer head; 38-Inlet temperature sensor; 39-Preload screw; 40-Steel ball. Detailed Implementation

[0085] The present invention will be further described below with reference to the embodiments.

[0086] A testing device for a spring-loaded safety valve, used to test safety valve 9, wherein safety valve 9 is prior art, such as... Figure 2 As shown, the safety valve 9 includes a valve seat 11, a valve body 12, a valve disc 13, a bushing 14, a retaining ring 15, a guide sleeve 16, a valve stem 17, a valve cover 18, a lower spring seat 19, a spring 20, an upper spring seat 21, and an adjusting screw 22. The valve seat 11 has a flanged inlet, which is connected to a mating flange on a pressure pipeline or pressure vessel via studs and nuts. The valve body 12 is fixed to the valve seat 11 by welding or threading, and the valve cover 18 is connected to the valve body 12 via studs and nuts. The guide sleeve 16 is mounted on the valve body 12, and the valve disc 13 and bushing 14 are fixed to the valve stem 17. The retaining ring 15 is mounted on the valve stem 17 via a cotter pin, which limits excessive movement of the bushing 14. A clearance fit ensures the installation position and alignment of the valve disc 13, bushing 14, and guide sleeve 16. The bushing 14 and guide sleeve 16 guide and limit the valve opening height. The spring assembly consists of a lower spring seat 19, a spring 20, and an upper spring seat 21. The spring force is adjusted by adjusting the clamping amount of the adjusting screw 22. The spring force acts directly on the valve disc 13 through the valve stem 17.

[0087] The testing apparatus includes a pressure stabilizing pipeline system and a safety valve system. The pressure stabilizing pipeline system provides a stable test medium, such as gas, for the testing of safety valve 9, while the safety valve system acquires the performance data of safety valve 9.

[0088] like Figure 1As shown, the pressure stabilizing pipeline system includes a gas source 1, a gas storage tank 2, a shut-off valve 3, an electric diaphragm pressure regulating valve 4, a front electric shut-off valve 5, a test container 7, a rear electric shut-off valve 8, and a vent valve 10. In the direction of airflow, the gas source 1, gas storage tank 2, shut-off valve 3, electric diaphragm pressure regulating valve 4, front electric shut-off valve 5, mass flow sensor 6, test container 7, rear electric shut-off valve 8, and vent valve 10 are sequentially arranged and connected.

[0089] Gas source 1 is located upstream of gas storage tank 2, supplying gas to gas storage tank 2, which then temporarily stores the gas for testing. Shut-off valve 3 and the front electric shut-off valve 5 are used to control the connection / disconnection of the pipeline between gas storage tank 2 and test container 7. The difference is that shut-off valve 3 is used for manual control of the pipeline connection / disconnection, while the front electric shut-off valve 5 is used for electric control. During the test, shut-off valve 3 is normally open.

[0090] The electric diaphragm pressure regulating valve 4 is responsible for controlling the pressure of the pipeline between the gas storage tank 2 and the test container 7; the front electric shut-off valve 5 and the rear electric shut-off valve 8 are responsible for electrically controlling the opening and closing of the pipeline; the mass flow sensor 6 is used to measure the discharge volume in real time during the safety valve discharge process.

[0091] The test container 7 is equipped with a pressure sensor and provides a stable and sufficient air supply to the safety valve system. The rear electric shut-off valve 8 controls the rate of pressurization in the test container 7. The output of the rear electric shut-off valve 8 connects to the inlet of the safety valve 9 and the vent valve 10. After the experiment, opening the vent valve 10 allows the medium in the test apparatus to be discharged.

[0092] like Figure 2-6 As shown, the safety valve system includes an action performance testing component and a reseating impact force detection component.

[0093] The action performance testing component is mainly used to test the action performance of the safety valve 9, including inlet pressure sensor 23, inlet temperature sensor 38, outlet temperature sensor 24, laser displacement sensor 26, and acceleration sensor 25.

[0094] like Figure 2As shown, two NPT threaded holes are machined at the inlet of valve body 12 for mounting inlet pressure sensor 23 and inlet temperature sensor 38, respectively. In the circumferential direction of the valve body 12 inlet, inlet pressure sensor 23 and inlet temperature sensor 38 are 180° apart. In the airflow direction at the valve body 12 inlet, inlet pressure sensor 23 and inlet temperature sensor 38 are spaced a certain distance apart. Inlet pressure sensor 23 is used to detect fluctuations in the safety valve inlet pressure in real time; inlet temperature sensor 38 is used to detect fluctuations in the safety valve inlet temperature in real time. Outlet temperature sensor 24 is located at the outlet of valve body 12 and is used to detect the outlet temperature of safety valve 9. When installing inlet pressure sensor 23, inlet temperature sensor 38, and outlet temperature sensor 24, ensure they are properly installed and effectively sealed to valve body 12.

[0095] The accelerometer 25 is magnetically mounted on the lower end face of the lower spring seat 19 of the safety valve. The lower spring seat 19 is made of magnetic stainless steel or other magnetic materials that meet performance requirements, and the flatness and smoothness of the lower end face are strictly guaranteed. Since the valve stem 17 and the lower spring seat 19 move synchronously when the safety valve is activated, this mounting method enables real-time detection of the acceleration of the valve stem 17 during the operation of the safety valve 9.

[0096] like Figure 3 As shown, the laser displacement sensor 26 is mounted on the upper fixing bracket 27 of the displacement sensor using bolts and nuts. The lower fixing bracket 28 of the displacement sensor is welded to the upper fixing bracket 27 of the displacement sensor, and the lower fixing bracket 28 is mounted on the valve cover 18 using set screws 30. The laser displacement detection block 29, which works in conjunction with the laser displacement sensor 26, is threaded onto the upper end of the valve stem 17 and is adjustable up and down.

[0097] Specifically, such as Figure 4 , 5 As shown, the upper fixing bracket 27 of the displacement sensor is a stainless steel sheet in the shape of an angle steel bar, with a connecting hole 31 on the vertical surface and an upper fixing hole 32 on the horizontal surface. The laser displacement sensor 26 is fixed by bolts and nuts through the connecting hole 31. The lower fixing bracket 28 of the displacement sensor is cylindrical, with an open lower end and a closed upper end by an end plate; the coaxiality of the cylinder and the flatness of the end face are ensured during manufacturing. The upper end plate of the lower fixing bracket 28 of the displacement sensor has an elliptical lower fixing hole 33 and a light-transmitting hole 34, both of which are through holes, i.e., penetrating the upper end plate of the lower fixing bracket 28 of the displacement sensor.

[0098] The upper mounting bracket 27 and lower mounting bracket 28 of the displacement sensor are fixed together using bolts and nuts through the upper fixing hole 32 and the lower fixing hole 33. An aluminum laser displacement detection block 29 is threaded onto the end of the valve stem 17; this laser displacement detection block 29 is adjustable vertically. When installing the laser displacement sensor 26, ensure that the laser emitter and receiver are aligned with the light transmission hole 34. Adjust the position of the laser displacement detection block 29 to ensure that the displacement detection surface is within the range of the laser displacement sensor 26, and that the laser displacement detection block 29 does not collide with the laser displacement sensor 26 after the valve opens. After adjusting the laser displacement detection block 29 to the appropriate position, fix it with the nut below to reduce vibration generated during valve opening.

[0099] The back-seating impact force detection assembly includes an impact force sensor 35, a preload bolt 36, a hammer head 37, and a steel ball 40.

[0100] The impact sensor 35 is a piezoelectric impact sensor, and the installation method of the impact sensor 35 is as follows. Figure 6 As shown. The lower end face of the valve stem 17 is machined into a flat surface and threaded. Simultaneously, a notch is milled on one side of the valve disc 13 to allow the data line of the impact force sensor 35 to pass through. The data line of the impact force sensor 35 exits through this notch, the vent hole of the bushing 14, and the back pressure adjustment hole of the valve cover 18. The data line of the impact force sensor 35 can also be wired according to the structure of the safety valve 9, as long as it does not affect the use of the impact force sensor 35 or the performance of the safety valve 9. After applying grease to both ends of the preload bolt 36, one end is screwed into the valve stem 17. The impact force sensor 35 is annular and is mounted on the preload bolt 36. The other end of the preload bolt 36 is tightened to the hammer head 37. The impact force sensor 35, valve stem 17, and hammer head 37 form a rigid connection by applying preload. The hammer head 37 has a ball socket, which, together with the steel ball 40, ensures the centering effect of the impact force sensor 35.

[0101] To reduce the vibration between the impact sensor 35 and the valve stem 17 and reduce the test error, the impact sensor 35 is pre-tightened by the hammer head 37 to form a rigid connection between the hammer head 37, the impact sensor 35 and the valve stem 17. The pre-tightening force should not be less than 1 / 4 of the sensor's test range.

[0102] Threaded holes are machined on the valve disc 13 and the retaining ring 15, while a smooth hole is machined on the bushing 14. The diameter of the smooth hole is slightly larger than that of the threaded hole. These are connected by preload screws 39, securing the valve disc 13 and the bushing 14 together. This method prevents relative rotation between the valve disc 13, the bushing 14, and the valve stem 17, avoiding damage to the impact sensor 35, while also preserving a certain amount of oscillation, which is beneficial for the valve's operation.

[0103] like Figure 7 ,8 As shown, the power supply module mainly supplies power to the mass flow sensor 6, impact force sensor 35, inlet pressure sensor 23, inlet temperature sensor 38, outlet temperature sensor 24, laser displacement sensor 26, and acceleration sensor 25. The PLC system is mainly used to collect signals from the above sensors and also to control the opening degree of the front electric shut-off valve 5 and the rear electric shut-off valve 8.

[0104] The data acquisition system includes a power supply module, a PLC system, and a host computer. The power supply module converts 220V voltage to 24V to power the aforementioned sensors. The PLC system collects signals from these sensors, and the PLC system and host computer transmit data via RS485. The voltage conversion by the power supply module, the power supply to the sensors, and the signal transmission from the sensors via the PLC system are all existing technologies and lack innovation. For example, the 220V power supply is converted to 24V by the power supply module. This 24V power supplies the mass flow sensor 6, impact force sensor 35, inlet pressure sensor 23, inlet temperature sensor 38, outlet temperature sensor 24, laser displacement sensor 26, and acceleration sensor 25. The voltage signals from the acceleration sensor 25, impact force sensor 35, mass flow sensor 6, and laser displacement sensor 26 are processed by a voltage signal conditioning circuit and then transmitted to the PLC system. The current signals from the inlet pressure sensor 23, inlet temperature sensor 38, and outlet temperature sensor 24 are processed by a current signal conditioning circuit and then transmitted to the PLC system. The PLC system then transmits the data to the host computer via RS485.

[0105] The test method for testing a spring-loaded safety valve using the above-mentioned test device includes the following steps:

[0106] Step 1: Bring the pressure in test container 7 to the preset pressure;

[0107] Start the system and set the test pressure for the safety valve to be tested;

[0108] Open the upstream shut-off valve 3 and the front electric shut-off valve 5 of the test container 7, and close the rear electric shut-off valve 8. Gas is supplied to the test container 7 from the gas storage tank 2. The PLC system sends a control signal to make the electric shut-off valve 5 open to its maximum. The pressure sensor in the test container 7 judges the gas pressure in the test container 7. When the pressure in the test container 7 reaches 80% of the test set pressure, the PLC system sends a control signal to reduce the opening of the electric shut-off valve 5, thereby slowing down the gas intake of the test container 7 and reducing pressure fluctuations. When the gas pressure in the test container 7 reaches the set pressure, the PLC system sends a signal to control the electric shut-off valve 5 to close. At this time, the pressure in the pressure container 7 is stabilized at the set pressure.

[0109] Step 2: Opening and releasing the safety valve;

[0110] The PLC system controls the front electric shut-off valve 5 to close and the rear electric shut-off valve 8 to open, allowing gas to flow out of the test container 7. Because the gas pressure inside the pressure container 7 is higher than the set pressure for the safety valve 9 to open, the safety valve 9 opens and discharges the medium. The pressure inside the test container 7 is much higher than the set pressure for the safety valve 9 to open, causing the safety valve to reach full opening and enter a stable discharge phase. The PLC system collects data from the mass flow sensor 6, inlet pressure sensor 23, inlet temperature sensor 38, outlet temperature sensor 24, laser displacement sensor 26, and acceleration sensor 25 during the test.

[0111] The collected data is processed by the host computer to obtain the inlet pressure, inlet and outlet temperatures, valve stem displacement curves, and mass flow rate during the opening and discharge process of safety valve 9. The analysis is used to determine whether the opening of safety valve 9 is accurate and whether the discharge process is stable.

[0112] Step 3: Reseating the safety valve;

[0113] As safety valve 9 releases air, the pressure inside test container 7 continuously decreases, and safety valve 9 begins to reseat until it re-seales.

[0114] The PLC system collects data from the inlet pressure sensor 23, laser displacement sensor 26, acceleration sensor 25, and impact force sensor 35 during the test. The collected data is processed by the host computer to obtain the data of the inlet pressure, valve stem displacement, and valve stem acceleration of the safety valve 9 during the reseating process, as well as the value recorded by the impact force sensor at the moment of the safety valve reseating.

[0115] Step 4: Analyze and obtain the force on the valve seat during the safety valve reseating process;

[0116] During this experiment, the impact force sensor 35 was not directly installed on the impact force application surface. Therefore, the measured value only represents the impact effect generated by the impact force sensor 35 and all moving parts above it, rather than the impact effect generated by all moving parts. During the reseating process of the safety valve 9, the inlet medium always supports the moving parts. In order to obtain the impact effect at the moment of valve reseating, it is necessary to perform mathematical deduction on the measured value of the impact force sensor.

[0117] The force analysis of the valve seat during the reseating process of safety valve 9 is as follows: Figure 9 As shown, the correction process is as follows:

[0118] Calculate the total mass m of the moving parts 总 :

[0119]

[0120] In the formula:

[0121] m 阀杆 It is the mass of valve stem 17;

[0122] m 阀瓣 It is the mass of valve disc 13;

[0123] m 传感器 It is the total mass of the impact sensor 35, the preload bolt 36, and the hammer head 37;

[0124] m 下弹簧座 It is the mass of the lower spring seat 19;

[0125] m 弹簧 That is the mass of spring 20;

[0126] The force F exerted by the medium on valve disc 13 is calculated. 介质 :

[0127] F 介质 =P·S 密封

[0128] In the formula:

[0129] P is the inlet pressure of the safety valve;

[0130] S 密封 The sealing area of ​​the safety valve;

[0131] Calculate and obtain partial impact force F 部冲 :

[0132] F 部冲 =F 实测 -F 弹簧

[0133] In the formula:

[0134] F 实测 The resultant force measured by the impact force sensor 35;

[0135] F 弹簧 This refers to the spring preload.

[0136] Real Impact F 总冲 :

[0137]

[0138] In the formula:

[0139] m 总 It is the total mass of the moving parts;

[0140] m 阀瓣 It is the mass of valve disc 13;

[0141] m 传感器 It is the total mass of the impact sensor 35, the preload bolt 36, and the hammer head 37;

[0142] F部冲 It is part of the impact force;

[0143] The actual resultant force F on the valve seat 座 :

[0144] F 座 =F 总冲 +F 弹簧 -F 介质 +m 总 g

[0145] In the formula:

[0146] F 总冲 It's a real impact;

[0147] F 弹簧 This refers to the spring preload.

[0148] F 介质 It is the force exerted by the medium on valve disc 13;

[0149] m 总 It is the total mass of the moving parts.

[0150] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make possible changes and modifications to the technical solutions of the present invention by utilizing the methods and techniques disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solutions of the present invention shall fall within the protection scope of the technical solutions of the present invention.

Claims

1. A testing device for a spring-loaded safety valve, used to test a safety valve (9), the safety valve (9) comprising a valve seat (11), a valve body (12), a valve disc (13), a bushing (14), a retaining ring (15), a guide sleeve (16), a valve stem (17), a valve cover (18), a lower spring seat (19), a spring (20), an upper spring seat (21), and an adjusting screw (22); characterized in that: The testing device includes a pressure stabilizing pipeline system and a safety valve system; The pressure stabilizing pipeline system is used to provide the test medium to the safety valve (9); the pressure stabilizing pipeline system includes a gas storage tank (2), an electric diaphragm pressure regulating valve (4), a front electric shut-off valve (5), a mass flow sensor (6), a test container (7), and a rear electric shut-off valve (8); in the direction of airflow, the gas storage tank (2), the electric diaphragm pressure regulating valve (4), the front electric shut-off valve (5), the mass flow sensor (6), the test container (7), and the rear electric shut-off valve (8) are arranged in sequence and connected; the output end of the rear electric shut-off valve (8) is connected to the input port of the safety valve (9); The safety valve system includes an action performance testing component and a reseating impact force detection component; The motion performance testing component includes An inlet pressure sensor (23) is used to detect the pressure at the inlet of the safety valve (9); An inlet temperature sensor (38) is used to detect the temperature at the inlet of the safety valve (9); An outlet temperature sensor (24) is used to detect the temperature at the outlet of the safety valve (9); A laser displacement sensor (26) is used to detect the displacement of the valve stem (17); And an acceleration sensor (25) for detecting the acceleration of the valve stem (17) as it moves; The back-seating impact force detection assembly includes an impact force sensor (35), a pre-tightening bolt (36), a hammer (37), and a steel ball (40). During testing, the impact force sensor (35) is mounted on the pre-tightening bolt (36), one end of which is fixedly connected to the valve stem (17), and the other end is fixedly connected to the hammer (37). The impact force sensor (35) is located between the hammer (37) and the valve stem (17), and a pre-tightening force is applied to the impact force sensor (35) by the hammer (37). The lower side of the hammer (37) is provided with a ball socket, and the steel ball (40) is located between the ball socket and the valve disc (13).

2. The testing device for a spring-loaded safety valve according to claim 1, characterized in that: The pressure stabilizing pipeline system also includes a vent valve (10), which is connected to the output end of the rear electric shut-off valve (8) for venting.

3. The testing device for a spring-loaded safety valve according to claim 1, characterized in that: The pressure stabilizing pipeline system also includes a shut-off valve (3), which is located on the pipeline between the gas storage tank (2) and the test container (7) and is used to manually control the opening and closing of the pipeline.

4. The testing device for a spring-loaded safety valve according to claim 1, characterized in that: The accelerometer (25) is magnetically attached to the lower end face of the lower spring seat (19).

5. A testing device for a spring-loaded safety valve according to claim 1, characterized in that: In the circumferential direction of the valve body (12) inlet, the inlet pressure sensor (23) and the inlet temperature sensor (38) are set at a distance of 180°; in the inlet airflow direction of the valve body (12), the inlet pressure sensor (23) and the inlet temperature sensor (38) are set at a distance.

6. A testing device for a spring-loaded safety valve according to claim 1, characterized in that: The preload applied by the hammer (37) to the impact force sensor (35) should be no less than 1 / 4 of the test range of the impact force sensor (35).

7. A test method using a test apparatus for a spring-loaded safety valve as described in any one of claims 1 to 6, characterized in that: After completing the assembly of the safety valve (9) and the testing device, perform the following steps in sequence: Step 1: Bring the pressure in the test container (7) to the preset pressure; Step 2: Safety valve (9) is opened and discharged; Control the gas outflow in the test container (7); gradually open the safety valve (9) and discharge the medium until it reaches the full opening height and enters the stable discharge stage; collect the inlet pressure, inlet temperature, outlet temperature, valve stem displacement and mass flow rate during the opening and discharge process of the safety valve (9) during the test, and analyze and judge whether the opening of the safety valve (9) is accurate and whether the discharge process is stable; Step 3: Safety valve reseating; As the safety valve (9) discharges, the air pressure inside the test container (7) continuously decreases, and the safety valve (9) begins to reseat until it re-seals; the inlet pressure, valve stem displacement and valve stem acceleration, as well as the instantaneous impact force during the reseat process of the safety valve (9) are collected; Step 4: Analyze and obtain the force on the valve seat during the safety valve reseating process.

8. The test method according to claim 7, characterized in that: The fourth step, analyzing and obtaining the force on the valve seat during the safety valve reseating process, includes the following steps: Calculate the total mass of the moving parts : In the formula: It is the mass of the valve stem (17); It is the mass of the valve disc (13); It is the total mass of the impact sensor (35), the preload bolt (36), and the hammer (37); It is the mass of the lower spring seat (19); It is the mass of the spring (20); The force exerted by the medium on the valve disc (13) is calculated. : In the formula: P is the inlet pressure of the safety valve; The sealing area of ​​the safety valve; Calculation yields partial impact force : The resultant force was measured by the impact force sensor (35); This refers to the spring preload. Real impact : In the formula: It is the total mass of the moving parts; It is the mass of the valve disc (13); It is the total mass of the impact sensor (35), the preload bolt (36), and the hammer (37); It is part of the impact force; The actual resultant force on the valve seat In the formula: It's a real impact; This refers to the spring preload. It is the force exerted by the medium on the valve disc (13); It is the total mass of the moving parts.

9. The test method according to claim 7, characterized in that: The first step includes the following steps: Start the system and set the test pressure of the safety valve (9) to be tested; Open the upstream electric shut-off valve (5) of the test container (7) and close the downstream electric shut-off valve (8) to supply gas into the test container (7) from the gas storage tank (2); When the opening of the electric shut-off valve (5) reaches its maximum, the gas pressure inside the test container (7) is determined by the pressure sensor in the test container (7); When the pressure inside the test container (7) reaches 80% of the test set pressure, the opening of the control front electric shut-off valve (5) is reduced, thereby slowing down the air intake of the test container (7) and reducing pressure fluctuations. When the air pressure in the test container (7) reaches the set pressure, the electric shut-off valve (5) is closed and the pressure in the test container (7) stabilizes at the set pressure.

10. The test method according to claim 7, characterized in that: In the second step, the inlet pressure, inlet temperature, outlet temperature, valve stem displacement curve and mass flow rate during the opening and discharge process of the safety valve (9) are collected by the inlet pressure sensor (23), inlet temperature sensor (38), outlet temperature sensor (24), laser displacement sensor (26), acceleration sensor (25) and mass flow sensor (6).

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