CN115200804A

CN115200804A - Safety valve online detection system and detection method

Info

Publication number: CN115200804A
Application number: CN202110393877.1A
Authority: CN
Inventors: 黎远中; 罗飞飞; 吴芳芳; 李仁源; 杨文文; 蒋建武; 祁治中; 崔德耀; 白璐
Original assignee: Xinjiang Xinte Crystal Silicon High Tech Co ltd; Xinte Energy Co Ltd
Current assignee: Xinjiang Xinte Crystal Silicon High Tech Co ltd; Xinte Energy Co Ltd
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2022-10-18

Abstract

The invention discloses a safety valve on-line detection system and a detection method, wherein the system comprises: the medium storage unit is used for storing a medium for detecting the safety valve; the conveying pipeline is connected with the medium storage unit; the cavity is connected with the medium storage unit through a conveying pipeline, the inlet of the cavity is connected with the medium storage unit through the conveying pipeline, and the first outlet of the cavity is used for being connected with the inlet of a safety valve to be detected; the first valve is arranged on the conveying pipeline between the medium storage unit and the cavity; the second valve is arranged on the connecting pipeline of the second outlet of the cavity; the first pressure detection unit is used for detecting the pressure of the medium in the cavity and sending the pressure to the control unit; the control unit is used for controlling the pressure in the cavity to be preset pressure by adjusting the first valve and the second valve, and detecting the on-line tripping pressure and the sealing test of the safety valve. The system and the method have high detection accuracy and minimize error factors. The detection accuracy is improved by selecting an instrument with high precision grade and reasonably calibrating the detector.

Description

Safety valve online detection system and detection method

Technical Field

The invention belongs to the technical field of safety valve detection, and particularly relates to an online detection system and method for a safety valve.

Background

With continuous progress of scientific technology, the production scale of modern enterprises is gradually enlarged, production devices in the industries of petroleum, chemical engineering, energy and the like develop in a large-scale direction, and the requirements on safety and environmental protection are higher and higher.

At present, almost all commercial safety valve online detection technologies are at the core, a hydraulic oil cylinder is used for clamping or a pneumatic valve rod of a safety valve is used for clamping, a valve core of the safety valve is enabled to be opened, and when the opening state is judged, a computer data acquisition system is used for detecting, so that the field detection without dismounting the safety valve is realized.

The existing commercial safety valve online check meter mainly comprises a mechanical clamp, a hydraulic power unit and a data acquisition and processing unit, wherein the mechanical clamp is mainly used for clamping and positioning a safety valve, an external force actuator is provided for a hydraulic system, and various clamps with different specifications and sizes are prepared according to different specifications of the safety valve. The mechanical clamp adopts a combined structure, and is convenient to disassemble and assemble, safe and reliable. The hydraulic power unit consists essentially of a manual/automatic pump that provides adjustable hydraulic output and flow to control applied lift force and lift speed. The data acquisition processing unit can set and acquire related parameters, and the tension sensor adopts a spoke type structure, so that the precision can reach 0.05%.

In the prior art, the safety valve is detected on line by using a medium in a pressure container, the medium containing particles or impurities in inflammable, explosive, poisonous and harmful gases and fluids cannot be detected on line, and the sealing test pressure value of the safety valve cannot be detected on line.

Disclosure of Invention

The invention aims to solve the technical problem of providing an online detection system and a detection method for a safety valve, aiming at the defects in the prior art, the online detection of the sealing test pressure of the safety valve is realized, and the online detection system and the online detection method can be used for detecting flammable, explosive, toxic and harmful gas and media containing particles or impurities in fluid by using externally added nitrogen as a test medium and are used for online detection of the sealing test pressure value of the safety valve.

The technical scheme adopted for solving the technical problem of the invention is to provide an online detection system for a safety valve, which comprises the following components:

a medium storage unit for storing a medium for safety valve detection;

the conveying pipeline is connected with the medium storage unit and is used for conveying a medium for safety valve detection;

the cavity is connected with the medium storage unit through pipeline, and the cavity is used for buffer memory relief valve to detect and uses the medium, and the cavity includes: the device comprises a cavity body, a cavity inlet, a cavity first outlet and a cavity second outlet, wherein the cavity inlet, the cavity first outlet and the cavity second outlet are arranged on the cavity body;

the first valve is arranged on the conveying pipeline between the medium storage unit and the cavity and used for supplementing air into the cavity;

the second valve is arranged on a connecting pipeline of a second outlet of the cavity and used for relieving pressure of the cavity;

the first pressure detection unit is arranged on the conveying pipeline between the first valve and the cavity and close to the inlet of the cavity, and is used for detecting the medium pressure in the cavity and sending the medium pressure to the control unit;

and the control unit is used for controlling the pressure in the cavity to be preset pressure by adjusting the first valve and the second valve, and detecting the on-line tripping pressure and the sealing test of the safety valve. Wherein, the relief valve is the spring relief valve.

Preferably, the medium storage unit includes: the holding vessel, the relief pressure valve of being connected with the holding vessel, the holding vessel is connected with the cavity, and the holding vessel is used for storing the relief valve and detects and use the medium, and the relief pressure valve sets up on the delivery line between holding vessel and cavity, and is located first valve upper reaches, and required pressure when the relief valve detects is convenient for to the gas decompression of holding vessel decompression to the relief pressure valve.

Preferably, the first pressure detecting unit includes: the pressure detection module is used for detecting the pressure in the cavity and sending the pressure to the control unit, the first display module is used for displaying the pressure value received by the control unit, and when the pressure in the cavity exceeds the alarm pressure value, the control unit controls the alarm module to send out an alarm instruction and automatically adjusts the opening of the second valve to release the pressure.

Preferably, the safety valve online detection system further includes: and the second pressure detection unit is arranged on the conveying pipeline between the first valve and the cavity and is used for detecting and displaying the pressure in the input pipeline.

Preferably, the first quick coupling is arranged on the input pipeline between the first valve and the medium storage unit;

and the second quick joint is arranged on the input pipeline between the second pressure detection unit and the cavity.

Preferably, the safety valve online detection system further includes: a mounting bracket for supporting the mounting cavity, the mounting bracket comprising: the cavity further comprises a base arranged below the cavity body, and the three-jaw clamp is connected with the base.

The invention also provides a detection method using the safety valve online detection system, which comprises the following steps:

connecting a safety valve inlet of a safety valve to be detected with a first outlet of the cavity, and providing a medium for detection through a medium storage unit;

and the control unit adjusts the first valve and the second valve to control the pressure in the cavity to be preset pressure, the safety valve is subjected to sealing test detection of on-line tripping and falling pressure, and if the sealing test detection of the on-line tripping and falling pressure is qualified, the safety valve is subjected to sealing test detection of on-line recoil pressure.

Preferably, the installation position of the cavity is the position of a rupture disk or a flange short section with a clamp arranged between the safety valve to be detected and the root valve.

Preferably, the specific method for performing the sealing test detection of the online tripping-back pressure on the safety valve in the step is as follows:

the method comprises the steps of opening a first valve, closing a second valve, providing a detection medium through a medium storage unit, when the safety valve to be detected is started to jump back and fall, if the first pressure detection unit detects that the pressure in a cavity is first preset pressure, controlling the first valve to be closed by a controller, detecting the sealing performance of sealing points of a pipeline and a part from the medium storage unit to the safety valve, a pipeline and a part from the cavity to a connecting pipeline of an outlet of the second valve, and the part, and if the first preset pressure is unchanged within first preset time, the sealing test is qualified, otherwise, the sealing test is unqualified.

Preferably, in the step of performing the sealing test detection of the online tripping-back pressure on the safety valve, if the first pressure detection unit detects that the pressure in the cavity is greater than a first preset pressure, the control unit opens the second valve for pressure relief until the first pressure detection unit detects that the pressure in the cavity is the first preset pressure, and then automatically closes the second valve;

if the first pressure detection unit detects that the pressure in the cavity is smaller than the first preset pressure, the control unit opens the first valve to supplement air until the first pressure detection unit detects that the pressure in the cavity is the first preset pressure, and then closes the first valve.

Preferably, the first predetermined pressure is 0.9 times the kick-off pressure (1 + ± 0.10%) KPa and the first predetermined time is 3 to 10 minutes.

Preferably, the specific method for performing the seal test detection of the online recoil pressure on the safety valve in the step is as follows:

the method comprises the steps of opening a first valve, closing a second valve, providing a detection medium through a medium storage unit, when a safety valve to be detected returns to a seat, if the pressure in a cavity detected by a first pressure detection unit is a second preset pressure, controlling the first valve to be closed by a controller, detecting the sealing performance of sealing points of a pipeline and a part from the medium storage unit to the safety valve, a pipeline and a part from the cavity to a connecting pipeline of an outlet of the second valve, and if the second preset pressure is not changed within a second preset time, the sealing test is qualified, otherwise, the sealing test is unqualified.

Preferably, the second predetermined pressure is 0.9 times the kick-off pressure (1 + ± 0.10%) KPa and the second predetermined time is 3 to 10 minutes.

Preferably, the method further comprises the following steps if the safety valve is tested by a seal test under the condition of online recoil pressure, and if the test result is not qualified:

if particles or impurities exist on a sealing surface between the valve core and the valve seat of the safety valve, purging the sealing surface between the valve core and the valve seat of the safety valve at least twice through nitrogen, performing sealing test detection of online recoil pressure on the safety valve by using the same method, and if the sealing test is not qualified, detaching the safety valve, repairing or replacing corresponding parts, and then performing sealing test detection of the safety valve online detection system again.

The safety valve on-line detection system and the detection method have the beneficial effects that:

the safety valve which is applied for long-period operation for more than one year in delay is subjected to non-stop on-line starting pressure and sealing pressure detection, so that the requirements of relevant laws and regulations are met, and the requirements of relevant administrative departments on at least one verification of the safety valve in use every year are met.

When the safety valve is subjected to offline cold-state verification at normal temperature and normal pressure, the following field practical problems can be solved by using the safety valve online detection device:

(1) in order to save large overhaul time, safety valves which do not need to be overhauled are screened out before large overhaul is started to stop for online detection, especially the safety valves with large calibers and high installation positions are planned to be arranged for online detection when the safety valves are not overhauled, so that not only is time saved for the large overhaul, but also the construction period and the cost of disassembly, hoisting and safety are reduced (taking the calibers of a rectification unit of a certain crystalline silicon 3.6 million tons/year project at present as more than 80mm, taking the safety valves with special installation positions as examples, and through measurement and calculation, auxiliary costs of cranes and the like are saved by at least 30 million yuan every year);

(2) if the tripping pressure of the safety valve after being set on the off-line calibration console is changed frequently due to the influence of links such as transportation, in-place installation and the like on the safety valve, the detection system and the detection method designed by the invention are utilized to detect the tripping pressure and the sealing pressure of the safety valve again before the feeding and the starting;

(3) the valve clack frequency jump or flutter of the safety valve caused by too large spring stiffness of the safety valve is detected on line by starting jump and sealing after a spring with proper stiffness is used on site; or the regulating ring of the safety valve is improperly regulated, so that the valve clack frequency jump or vibration of the safety valve is caused due to overhigh recoil pressure, and after the position of the regulating ring is readjusted, the tripping and sealing detection are carried out on line again.

The safety valve online detection system and the detection method have high detection accuracy, and error factors are reduced to the minimum. The detection accuracy is improved by selecting an instrument with higher precision grade, reasonably calibrating the detector and the like.

Drawings

Fig. 1 is a schematic structural diagram of an online detection system for a safety valve in embodiment 2 of the present invention;

FIG. 2 is a schematic structural view of a cavity in embodiment 2 of the present invention;

FIG. 3 is a schematic structural view of a safety valve on-line detection system in embodiment 2 of the present invention during a sealing test before use;

fig. 4 is a schematic structural diagram of an online safety valve detection system according to embodiment 2 of the present invention during simulation detection;

fig. 5 is a front view of a mounting platform of an online safety valve detection system in embodiment 2 of the present invention;

fig. 6 is a plan view of a mounting platform of an online safety valve detection system according to embodiment 2 of the present invention;

fig. 7 is a front view of a three-jaw chuck of the safety valve online detection system in embodiment 2 of the present invention;

FIG. 8 is a top view of a three-jaw clamp of an online safety valve detection system according to embodiment 2 of the present invention;

fig. 9 is a schematic structural diagram of a base of an online safety valve detection system in embodiment 2 of the present invention.

In the figure: 1-high pressure nitrogen cylinder; 2-a pressure reducing valve; 3-a first quick coupling; 4-a first valve; 5-a first ball valve; 6-a pressure sensor; 7-a second quick coupling; 8-safety valve; 9-a cavity; 10-a third ball valve; 11-a second valve; 12-a second ball valve; 13-safety valve relief buffer tank; 14-a fifth ball valve; 15-pressure gauge; 16-a fourth ball valve; 17-a safety valve; 18-a pressure vessel; 19-high pressure hose; 20-a steel pipe; 21-a gasket; 22-stud bolts; 23-external thread joint; 24-an internal thread joint; 25-bend; 26-pressure gauge connection; 27-a tee joint; 28-pressure switch; 29-a tee joint; 30-a blind plate; 31-a blind flange; 32-a base; 33-three-jaw clamp; 34-stud bolts; 35-mounting a platform; 36-plate; 37-a leg; 38-foot plate; 39-blind flange; 40-a steel pipe; 41-cylinder.

Detailed Description

In order to make the technical solutions of the present invention better understood, the present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

Reference will now be made in detail to embodiments of the present patent, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are illustrative only for the purpose of explaining the present patent and are not to be construed as limiting the present patent.

Example 1

The embodiment provides a relief valve on-line measuring system, includes:

a medium storage unit for storing a medium for safety valve detection;

the delivery pipeline is connected with the medium storage unit and used for delivering a medium for detecting the safety valve;

and the control unit is used for controlling the pressure in the cavity to be preset pressure by adjusting the first valve and the second valve, and detecting the on-line tripping pressure and the sealing test of the safety valve.

The embodiment also provides a detection method using the safety valve online detection system, which comprises the following steps:

and the control unit adjusts the first valve and the second valve to control the pressure in the cavity to be preset pressure, the safety valve is subjected to sealing test detection of on-line tripping back pressure, and if the sealing test detection of the on-line tripping back pressure is qualified, the safety valve is subjected to sealing test detection of on-line back pressure.

The safety valve online detection system and the detection method in the embodiment have the beneficial effects that:

Example 2

As shown in fig. 1 to 9, the present embodiment provides an online safety valve detection system, which includes:

a medium storage unit for storing a medium for detection by the safety valve 8;

the conveying pipeline is connected with the medium storage unit and is used for conveying a medium for detection of the safety valve 8;

cavity 9 is connected with the medium storage unit through the conveying line, and cavity 9 is used for buffering 8 detection of relief valve and uses the medium, and cavity 9 includes: the device comprises a cavity body, a cavity inlet, a cavity first outlet and a cavity second outlet, wherein the cavity inlet, the cavity first outlet and the cavity second outlet are arranged on the cavity body;

the first valve 4 is arranged on a conveying pipeline between the medium storage unit and the cavity 9 and used for supplying air into the cavity 9; specifically, the first valve 4 in this embodiment is an electric control valve for supplying air.

The second valve 11 is arranged on a connecting pipeline of the second outlet of the cavity and used for relieving the pressure of the cavity 9; specifically, in this embodiment, the second valve 11 is an electric control valve for pressure relief.

The first pressure detection unit is arranged on the conveying pipeline between the first valve 4 and the cavity 9 and close to the inlet of the cavity, and is used for detecting the medium pressure in the cavity 9 and sending the medium pressure to the control unit;

and the control unit is used for controlling the pressure in the cavity 9 to be preset pressure by adjusting the first valve 4 and the second valve 11, and detecting the on-line tripping pressure and the sealing test of the safety valve 8.

Specifically, the safety valve 8 in this embodiment is a spring-type safety valve, and is a spring-type direct load safety valve.

Preferably, the medium storage unit includes: the holding vessel, the relief pressure valve 2 of being connected with the holding vessel, the holding vessel is connected with cavity 9, and the holding vessel is used for storing 8 detection of relief valve and uses the medium, and relief pressure valve 2 sets up on the pipeline between holding vessel and cavity 9, and is located 4 upper reaches of first valve, and required pressure when relief pressure valve 2 is used for the gas decompression of holding vessel decompression is convenient for relief valve 8 to detect. Specifically, the storage tank in this embodiment is a high-pressure nitrogen gas cylinder 1, and the medium for detection is nitrogen gas.

Preferably, the first pressure detecting unit includes: the pressure detection module is used for detecting the pressure in the cavity 9 and sending the pressure to the control unit, the first display module is used for displaying the pressure value received by the control unit, and when the pressure in the cavity 9 exceeds the alarm pressure value, the control unit controls the alarm module to send out an alarm instruction and automatically adjusts the opening degree of the second valve 11 to release the pressure. Specifically, the first pressure detection unit in this embodiment is a pressure switch 28.

Preferably, the safety valve online detection system further includes: and the second pressure detection unit is arranged on the conveying pipeline between the first valve 4 and the cavity 9 and is used for detecting and displaying the pressure in the input pipeline. Specifically, the second pressure detecting unit in the present embodiment is located upstream of the first pressure detecting unit. Specifically, the second pressure detection unit in the present embodiment includes a pressure sensor 6 (with a pressure switch).

Preferably, a first quick coupling 3 is provided on the input line between the first valve 4 and the medium storage unit;

and the second quick connector 7 is arranged on an input pipeline between the second pressure detection unit and the cavity 9.

Preferably, the safety valve online detection system further includes: a mounting bracket for supporting the mounting cavity 9, the mounting bracket comprising: mounting platform 35, set up the three-jaw card 33 on mounting platform 35, cavity 9 still includes the base 32 that sets up under the cavity body, and three-jaw card 33 is connected with base 32.

Specifically, in this embodiment, a high-pressure nitrogen cylinder 1, a pressure reducing valve 2, a high-pressure hose 19, a first quick coupling 3, a steel pipe 20, a first valve 4, a second pressure detection unit, a second quick coupling 7, a first pressure detection unit, and a cavity 9 are connected in sequence. The second pressure detection unit is respectively connected with the first valve 4 and the second quick coupling 7 through a tee 27, and a first ball valve 5 is connected between the second pressure detection unit and the tee 27.

The first export of cavity communicates with each other with the import of 8 relief valves of the relief valve of examining, examines relief valve 8 and passes through the pipe connection through pipeline and relief valve discharge buffer tank 13, examines and is provided with second ball valve 12 on examining the pipeline between relief valve 8 and the relief valve discharge buffer tank 13, and the cavity second export is connected with second valve 11.

The cavity 9 further comprises a third cavity outlet arranged on the cavity body, the third cavity outlet is connected with the pressure container 18 through a pipeline, and a third ball valve 10 is arranged on the pipeline between the cavity 9 and the pressure container 18. The pressure container 18 is connected with a normal safety valve 17 through a pipeline, and a fourth ball valve 16 is arranged on the pipeline between the pressure container 18 and the normal safety valve 17. The pressure container 18 is connected with the pressure gauge 15 through a pipeline, and a fifth ball valve 14 is arranged on the pipeline between the pressure container 18 and the pressure gauge 15.

Specifically, in the safety valve online detection system of the present embodiment, the detection medium nitrogen provided by the high-pressure nitrogen cylinder 1 (with a special cylinder valve) passes through the pressure reducing valve 2, the high-pressure hose 19, the first quick coupling 3, the steel pipe 20, the first valve 4, the second quick coupling 7 enters the hollow cavity 9 of the detection system, the cavity 9 communicates with the inlet of the safety valve 8 to be detected, and the second valve 11 is utilized to detect the tripping pressure and the sealing test pressure of the safety valve 8, meanwhile, the nitrogen enters the second pressure detection unit (with a pressure switch) through the first ball valve 5, when the safety valve 8 to be detected detects, the third ball valve 10 is in a closed state, the second ball valve 12 is in a fully open state (and the fourth ball valve 16 on the pressure container 18 is in a fully open state, the safety valve 17 is in an operating state, the fifth ball valve 14 is in a fully open state and is connected with the pressure gauge 15, and the pressure at which the pressure container 18 in service is operated is measured and displayed). The first quick coupling 3 is connected with the pressure sensor 6 and the first quick coupling 3 is connected with the second quick coupling 11 through steel pipes 20.

The safety valve on-line detection system in the embodiment comprises the following components in part by weight:

(1) And selecting a high-pressure nitrogen cylinder 1 of the storage tank. As shown in FIG. 1, a high pressure nitrogen gas cylinder 1 (with a special cylinder valve) with a volume of 40L is selected to provide high pressure nitrogen gas for a detection system. Renting special seamless steel cylinders which are qualified by being checked by professional organizations related to the state and are within the period of validity of use;

(2) The pressure reducing valve 2 is selected. As shown in FIG. 1, the pressure reducing valve 2 is a standard pressure reducing valve for nitrogen gas, etc., and the pressure reducing valve is made of brass as the main body of FARFLOW 813<HPb59-1>And (4) preparing. The sizes of the internal thread of the inlet joint and the external thread of the cylinder valve of the FARFLOW 818 type pressure reducing valve are G5/8 ', the inner diameter of the joint is 5.5mm, the outlet joint is connected with the external thread of the high-pressure hose 19, the thread specification is G5/8', the inner diameter is 5.5mm, the maximum flow is 80m ³ H is the ratio of the total weight of the catalyst to the total weight of the catalyst. The body of the pressure reducing valve 2 is also provided with a high-pressure nitrogen meter and a low-pressure nitrogen meter which respectively indicate the pressure (i.e. the working pressure) in the high-pressure air chamber (i.e. in the nitrogen cylinder) and the low-pressure air chamber. The measuring range of the high-pressure nitrogen meter is 0-25 MPa. The measuring range of the low-pressure nitrogen meter is 0-4 MPa.

(3) The high-pressure hose 19 is selected. As shown in fig. 1, a high-pressure hose 19 is connected between the pressure reducing valve 2 and the first quick coupling 3, and a high-pressure steel wire hose with the outer diameter phi of 10mm is selected according to the setting pressure of the safety valve 8 to be detected; the maximum length is determined according to the highest installation position of the safety valve 8 to be detected, and the length of the safety valve is 40 meters in the embodiment; in the present embodiment, the male connector at one end of the high-pressure hose 19 is adapted to the female connector of the pressure reducing valve 2 with a female screw of G3/8 "size, and the male connector at the other end is adapted to the female connector of the first quick connector 3 with a female screw of G3/8" size.

(4) The steel pipe 20, the tee 27, the pressure gauge joint 26, the elbow 25 and the first valve 4. As shown in figure 1, the external thread G3/8 'at the other end of the first quick connector 3 is matched with the internal thread G3/8' at one end of the first valve 4, and the internal diameter is 6.0mm. The internal thread G3/8' at the other end of the first valve 4 is matched with the external thread and then welded with the steel pipe 20, the steel pipe 20 is welded with one end of a tee 27, the upper end of the tee 27 is welded with the first ball valve 5, the other end of the tee is welded with one end of a second quick connector 7, the other end of the second quick connector 7 is welded with the cavity 9 by the steel pipe 20, and a pipeline between the cavity 9 and the second valve 11 is formed by welding Q345 carbon steel or stainless steel metal pipelines phi 10 x 2 mm; the other upper end of the first ball valve 5 is respectively welded with 2 pressure gauge joints 26 through a welded tee 29, a welded 90-degree elbow 25 and a steel pipe 20, and then is connected with the external threads of the 2 pressure sensors 6 in a matching mode, and the threaded interface of each pressure gauge joint 26 is M20 x 1.5.

(5) The first quick coupling 3 and the second quick coupling 7 are selected. As shown in figure 1, the first quick joint 3 and the second quick joint 7 adopt quick joints with two open-close ends, and the quick joints are composed of a joint body, a one-way valve core, an outer sleeve, a steel ball, a spring and a seal. The inner cavity of the joint body is provided with a one-way valve, when the two joint bodies are separated, the valve core of the one-way valve extends outwards under the action of respective spring and is pressed against the tapered hole of the joint body, so that the passage is closed, and the fluid in the pipes at the two sides is sealed in the pipes and cannot flow out; when the two joint bodies are connected, the two push rods at the front end of the valve core of the one-way valve are collided to force the valve core to leave the conical holes of the joint bodies, so that the fluids in the pipes at two sides are communicated, the two joint bodies are locked by the steel balls, and when the two joint bodies work, the outer sleeve presses the steel balls in the U-shaped grooves of the joint bodies under the action of the spring to connect the joint bodies. The first quick coupling 3 and the second quick coupling 7 in this embodiment are open-close hydraulic quick couplings made of 304 stainless steel, and are also suitable for occasions where nitrogen is used as a medium. Nominal scaleThe pressure was 350kgf/cm ² The medium temperature is-20 to +80 ℃. Gauge G3/8", rated pressure (psi) 2000, corresponding to 20MPa. The external thread G3/8 'at the other end of the first quick connector 3 and the internal thread G3/8' at one end of the first valve 4 have the inner diameter size of 6.0mm and are matched with the first quick connector 3. The first quick connector 3 is connected with the cavity 9 after being connected with the steel pipe 20 through the inner thread connector 24, and the second quick connector 7 is connected with the cavity 9 after being connected with the steel pipe 20 through the outer thread connector 23.

(6) The first valve 4 and the second valve 11 are selected (the first ball valve 5 is a manual valve, and the nominal diameter and the nominal pressure of the manual valve are consistent with those of the first valve 4). As shown in figure 1, the first valve 4 and the second valve 11 are both electric control valves, the first valve 4 and the second valve 11 are connected with a pipeline by internal threads G3/8', and a special control valve with the inner diameter size of 6.0mm is connected with the pipeline without a ball valve and a butterfly valve. The electric regulating valve is formed by connecting and combining an electric actuating mechanism and a regulating valve, and then mechanically connecting, assembling, debugging and installing. A working power supply: DC24V, AC220V, AC380V and other voltage levels. Inputting a control signal: DC4-20MA or DC1-5V, feedback control signal: DC4-20MA (load resistance below 500 ohm); the valve is driven by receiving a signal (such as 4-20 mA) of an industrial automatic control system to change the sectional area between the valve core and the valve seat so as to control the process parameters of flow, temperature, pressure and the like of a pipeline medium, thereby realizing the automatic regulation function. The novel electric control valve actuator has a servo function, receives a unified 4-20mA or 1-5 V.DC standard signal, converts a current signal into corresponding linear displacement, automatically controls the opening of the control valve, and achieves continuous regulation of process parameters such as pressure, flow, temperature and the like of fluid in a pipeline; the electric regulating valve adopts international advanced standards such as API and the like. A valve with nominal diameter of 6mm, nominal pressure of 40.0Mpa and working temperature of-196-800 ℃, and the product material is 304 stainless steel.

(7) The second pressure detection unit is a pressure sensor 6, and the pressure sensor 6 is selected. As shown in FIG. 1, the pressure sensor 6 comprises a pressure transmitter capable of monitoring the pressure of gas in various working conditions. The measuring range of the PAW pressure transmission controller is-0.1-60 MPa (Max), and the measuring precision is as follows: accuracy class 0.1, 0.2, 0.5, accuracy class 0.5, temperature impact 0.07: + 0.07% FS/10 ℃, stability 0.10% FS/year, repeatability error 0.10% FS; the working voltage is DC24VDC, and the medium temperature is-20 ℃ to 85 ℃; the inlet pressure core body is used as a measuring unit, so that the precision is high, the linearity is good, and the impact resistance and the corrosion resistance are realized; the meter body is provided with an LED display and supports two-wire 4-20mA signal output.

(8) The first pressure detection unit is the pressure switch 28, and the pressure switch 28 is selected. As shown in fig. 1, an electronic intelligent pressure control switch with the advantages of simple operation, high intelligent degree, fast response, high precision and the like is proposed. The pressure switch 28 adopts the pressure sensor 6 and the transmission circuit with high precision and high stability, and then realizes the detection, display, alarm and control signal output of the medium pressure signal through the special CPU modular signal processing technology. The pressure switch 28 uses elastic elements such as a single-coil spring tube, a diaphragm capsule, a bellows, etc. Working principle of the pressure switch 28: when the pressure in the system is higher or lower than the rated safe pressure, the disc in the sensor instantaneously moves, the switch joint is pushed to be switched on or off through the connecting guide rod, when the pressure is reduced to or increased to the rated recovery value, the disc instantaneously resets, the switch automatically resets, or simply, when the measured pressure exceeds the rated value, the free end of the elastic element generates displacement, and the switch element is pushed directly or after comparison, so that the on-off state of the switch element is changed, and the purpose of controlling the measured pressure is achieved. The pressure switch 28 of this embodiment is normally closed. The pressure switch 28 can select and purchase the pressure value according to the actual requirement within the pressure range, and the pressure value is 4.0MPa in the example.

(9) The cavity 9 is selected. As shown in FIG. 2, a cavity 9 is made of 304 stainless steel in the embodiment, the wall thickness of the cavity 9 is slightly larger than that of a pressure container 18, the height of the cavity 9 is the same as that (55 mm) of a holder of the rupture disk, the outer diameter of the cavity 9 is the same as that (phi 150 mm) of the holder, the inner diameter of the cavity 9 is shown in detail in FIG. 2, phi 5mm is drilled in the cavity 9 in the direction of 180 degrees, the cavity is connected with a nitrogen pipe phi 10 phi 2mm, and the other drilled phi 5mm is welded with a second valve 11 phi 10 inlet pipe. The cavity 9 is dimensioned as shown in figure 2 below.

(10) The tee 27 is an equal-diameter tee: as shown in fig. 1, the material is the same as that of the steel pipe 20, 304 stainless steel is selected in this example, and the specification: outer diameter phi 10 × 10, inner bore diameter 6mm.

(11) The elbow 25: as shown in figure 1, the material is the same as that of the steel pipe 20, 304 stainless steel, 90-degree elbow 25, specification phi 10 x 2, inner hole diameter 6mm and the number of the inner holes is 2 in total.

(12) Pressure gauge head 26: as shown in fig. 1, the material is the same as that of the steel pipe 20, and in this example, 304 stainless steel is selected, the specification M20 × 1.5, the diameter of the inner hole is 6mm, and the number of the inner holes is 2 in total.

(13) Steel pipe 20: as shown in FIG. 1, stainless steel, i.e., 10X 2mm,304, having a total length of about 1200mm, was selected for this example.

(14) Gasket 21: as shown in FIG. 1, the material of the gasket 21 is determined according to the pressure setting of the safety valve 8, the medium used for detection, the temperature and other factors, the material may be selected from polytetrafluoroethylene, metal wound gasket composite polytetrafluoroethylene and metal gasket, the pressure grade is at least one grade higher than the pressure of the safety valve 8, and the metal wound gasket composite polytetrafluoroethylene is selected in this example. The gasket 21 is arranged at the joint of the cavity 9 and the inlet of the safety valve 8, the metal pad material is low-carbon steel, and the metal belt material is 0Cr18Ni9; nominal diameter is 100mm; nominal pressure 4.0MPa (40 bar); gasket 21 size standard GB/T4622.2-2003; it is marked as: winding pad D1222-DN100-PN40.

(15) Stud bolt 22: as shown in fig. 1, the material is Q345 or 304 stainless steel, and according to the safety valve 8 to be detected, the specification of the bolt used by the holder is the same, and in this example, the 8.8-grade high-strength stud 22 is selected, the material is Q345, and the specification is M18 × 180mm. The gasket 21 and the cavity 9 are fixed at the position of the clamp by a group of stud bolts 22 through upper and lower flanges of the clamp between the safety valve 8 and the third ball valve 10.

(16) The blind plate 30: as shown in FIG. 3, the material selected for this example is PTFE with a thickness of 3mm, the detection system simulates the sealing test before the detection and the application, and the blind plate 30 is used for sealing the cavity 9.

(17) Blind flange 31: as shown in FIG. 3, the material is Q345R, the nominal pressure is 4.0MPa, the nominal diameter is DN100mm, the detection system is used for sealing test before use, and the blind plate 30 is connected with the cavity 9 through the blind flange 31.

(18) The base 32: as shown in fig. 4 and 9, the detection system for analog mode adjustment or analog detection before use comprises: blind flange 39, steel tube 40, cylinder 41. The steel pipe 40 is a short section of a round steel pipe, and the blind flange 39 and the steel pipe 40, the steel pipe 40 and the cylinder 41, and the upper cover plate and the lower cover plate of the cylinder 41 and the cylinder shell are connected by welding; the base 32 is made of Q345R, the nominal pressure of the blind flange 39 is 4.0MPa, and the nominal diameter DN is 100mm; the circular steel pipe short section Q345R has the outer diameter of 120mm, the wall thickness of 10mm and the length of 150mm; the outer diameter of the cylinder is 340mm, the thicknesses of the upper cover plate, the lower cover plate and the wall are 20mm, the material is Q345R, and the surface roughness of the surface contact with the simulation platform 35 is 6.3.

(19) Three-jaw chuck 33: as shown in fig. 7 and 8, the number of the present example is three, the material Q345R, the surface roughness of the contact surface with the mounting platform 35, the cylindrical surface in the base 32, and the stud bolt 34 is 6.3, and the safety valve 8 is used for simulation debugging before online detection.

(20) As shown in fig. 4, in this example, 6 sets of M24 × 130mm high-strength bolts with performance class 8.8 are selected, and the three-jaw clamp 33 is connected with the mounting platform 35 through the stud bolts 34 for simulation debugging before online detection of the safety valve 8.

(21) Simulation test platform 35: as shown in fig. 4 to 6, it comprises a flat plate 36, a leg 37 and a foot plate 38, wherein the flat plate 36 is used for supporting the cavity 9, the leg 37 is arranged below the flat plate 36, and the foot plate 38 is connected with the bottom of the leg 37; the flat plate 36 in the embodiment is made of Q345R, the thickness is 40mm, the surface roughness is 6.3, three grooves are formed in the plane, the groove depth is 40mm, the groove width is 25mm, and the groove length is 125mm; the supporting legs 37 are made of Q345R, 100X 100mm square steel and 800mm in length; the foot plate 38 has a thickness of 40mm,200 × 200mm, and is fixed on a concrete floor or a steel plate by using an expansion bolt M20 × 110.

As shown in FIG. 3, preparation work (or detection sequence) before detection operation

1. After all elements of the detection system are cleaned and purged to be qualified, all the elements are assembled;

2. the first pressure detection unit and the second pressure detection unit in the checking detection system are required to be satisfied. The second pressure detection unit comprises two pressure sensors 6 with the same specification, the accuracy grade of the pressure sensors 6 is not lower than 1.0 grade, the measuring range of the pressure sensors 6 is 1.5-3.0 times of the check pressure of the safety valve 8 (the pressure sensors 6 must be checked regularly, and the checking period is 6 months);

3. the first pressure detection unit is used after being installed and electrified and checking that various parameters, measuring ranges and zero points are normal;

4. after the PLC is electrified and initialized, checking whether the running states of the CPU and each module are normal or not;

5. manually opening an inflation valve of the medium storage unit, and performing the tightness check on the set of line detection system to be qualified, as shown in fig. 3;

6. before the online detection system detects, the safety valve 8 is debugged off-line in a simulation mode, as shown in fig. 4. The detection accuracy of the system is improved by simulating, debugging and checking the sensitivity and accuracy of the first pressure detection unit and the second pressure detection unit. The simulation debugging step of the starting pressure or the setting pressure of the safety valve 8 comprises the following steps: (1) And (4) checking that all parts of the detection system are installed, and after the sealing test is qualified, keeping the parts in a normal state. (2) Setting a safety valve 8 check starting pressure value P1 on an upper computer interface of a control unit (PLC) (the starting pressure values of the safety valves 8 with different specifications are different, and the starting pressure values need to be set according to the actual safety valves 8), compiling whether the control logic of the starting acousto-optic indication lamp of the safety valves 8 is correct, and setting the control modes of the first valve 4 and the second valve 11 to be automatic. (3) Opening the medium storage unit to start inflation until pressure signals of a first pressure detection unit actual measurement pressure value P3 and a second pressure detection unit actual measurement pressure value P4 are within an error range of a starting pressure set value P1, namely within a range of P1 (1 +/-K%), if a starting indicator lamp is not on, checking whether actions of parts of a control logic, a wiring loop and a safety valve 8 are in fault, and if the faults exist, carrying out simulation debugging according to the steps again after normal processing. If the starting and jumping indicator light is on, the simulation debugging is normal, relevant debugging records are filled, the first valve 4 is manually closed, the second valve 11 is opened to remove redundant gas, and the system is restored to the state before the test. The start-jump test can be started on site (note: K% = +/-0.10%, and detection precision of the remote transmission pressure gauge 15 is guaranteed).

7. Checking a machine account of the safety valve 8 to be detected, and searching whether check records and report information such as the last detection date, the setting pressure, the sealing pressure, the installation position and the like are complete or not;

8. performing appearance inspection on the safety valve 8 to be detected (whether the lead seal of the safety valve 8 is intact, whether the lead seals of the valve before and after the inlet and the outlet of the safety valve 8 are intact and in a normal opening position, whether the safety valve 8 leaks, whether the outer surface of the safety valve is corroded, whether a rupture disc device is intact) and recording;

9. checking whether the start-jump prompt record of the safety valve 8 of the PLC upper computer system is displayed normally;

10. closing a front hand valve or a root valve at the inlet of the safety valve 8 and a rear hand valve (if the rear hand valve is not available, reducing the pressure from the safety valve 8 to the discharge buffer tank to zero);

11. and removing the rupture disk and the clamp.

The safety valve on-line detection system of the embodiment has the technical scheme that after a root valve (customarily called as root valve) connected with an inlet of a safety valve 8 between the safety valve 8 to be detected and a pressure container 18 is closed, a tool of the safety valve on-line detection system of the embodiment is installed, nitrogen with proper pressure is provided by a high-pressure nitrogen cylinder 1 as a detection medium, measures such as an automatic regulating valve and an automatic pressure detection control element are adopted to detect on-line tripping (setting) pressure and a sealing test of the safety valve 8 to be detected, the normal operation of the pressure container 18 in service is not influenced, and the pressure container 18 in service is protected by overpressure through another safety valve 17.

In the crystalline silicon production device in the specific embodiment, the tripping pressure of one safety valve 8 to be detected is 185KPa, and the inlet nominal diameter is equal to 100mm.

connecting a safety valve inlet of a safety valve 8 to be detected with a first outlet of a cavity 9, installing a designed safety valve online detection system tool at the spatial position of a rupture disc with a clamp when the safety valve 8 is in use, fixing the tool by a stud bolt 22 and a gasket 21 (adopting a new bolt with the same specification), and providing a medium for detection through a medium storage unit;

the pressure in the cavity 9 is controlled to be preset pressure by adjusting the first valve 4 and the second valve 11 through the control unit, the safety valve 8 is subjected to sealing test detection of on-line tripping-back pressure, and if the sealing test detection of the on-line tripping-back pressure is qualified, the safety valve 8 is subjected to sealing test detection of on-line returning-back pressure. The detection method does not affect the normal operation of the in-service pressure vessel 18, the pressure vessel 18 is connected with two safety valves, one safety valve is used, the other safety valve is standby, the standby safety valve 8 is subjected to online detection, and the pressure vessel 18 is subjected to overpressure protection through the used safety valve 17.

The safety valve online detection system and the detection method in the embodiment are particularly suitable for online detection of the spring type safety valve 8 arranged on the pressure container 18 filled with gas or gas-liquid mixed medium in the continuous production and operation device of large-scale petroleum, chemical and energy enterprises. In the prior art, two spring type safety valves are respectively arranged on a pressure container 18, one safety valve 8 is used, the other safety valve is standby, a root valve is required to be arranged at the inlet of each safety valve to be connected with the pressure container 18, and a clamp is arranged between the root valve and the inlet of the safety valve 8 to clamp a rupture disk or a flange short section.

Preferably, the installation position of the cavity 9 is the position where a rupture disc or a flange short section with a clamp is arranged between the safety valve 8 to be detected and the root valve.

Preferably, the specific method for performing the sealing test detection of the online tripping and dropping pressure on the safety valve 8 in the above steps is as follows:

the method comprises the steps of opening a first valve 4, closing a second valve 11, providing a detection medium through a medium storage unit, when a safety valve 8 to be detected is started, bounced and fallen, if the first pressure detection unit detects that the pressure in a cavity 9 is a first preset pressure, closing the first valve 4 through interlocking control by a controller, disconnecting a first quick coupling, automatically adjusting the second valve 11 to be still in a closed state, and detecting the sealing performance of sealing points of a pipeline and parts between the medium storage unit and the safety valve 8, and a pipeline and parts between the cavity 9 and a connecting pipeline of an outlet of the second valve 11, specifically detecting the sealing performance of the sealing points of the first quick coupling 3, the first valve 4, a first ball valve 5, a pressure sensor 6, a second quick coupling 7, the second valve 11 and a gasket 21, wherein before the detection system is started, an air tightness test is carried out according to a pressure 100-150 KPa higher than the jump pressure, and the detection system is qualified, if the first preset pressure is not changed within a first preset time, the sealing test is unqualified, and if the first preset pressure is not changed within a first preset time, the sealing test is not qualified.

Preferably, the first predetermined pressure is 0.9 times the kick-off pressure (1 + ± 0.10%) KPa and the first predetermined time is 3 to 10 minutes. The first preset time in this embodiment is 5 minutes.

Preferably, in the step of performing the sealing test detection of the online tripping-back pressure on the safety valve 8, if the first pressure detection unit detects that the pressure in the cavity 9 is greater than a first preset pressure, the control unit opens the second valve 11 for pressure relief until the first pressure detection unit detects that the pressure in the cavity 9 is the first preset pressure, and then automatically closes the second valve 11;

if the first pressure detection unit detects that the pressure in the cavity 9 is smaller than the first preset pressure, the control unit opens the first valve 4 to supplement air until the first pressure detection unit detects that the pressure in the cavity 9 is the first preset pressure, then closes the first valve 4, and rechecks the sealing performance of the sealing points of the first quick connector 3, the first valve 4, the first ball valve 5, the pressure sensor 6, the second quick connector 7, the second valve 11 and the gasket 21 in the system, if the first preset pressure is unchanged within the first preset time, the sealing test is qualified, and if the first preset pressure is not changed within the first preset time, the sealing test is unqualified.

Preferably, the specific method for performing the seal test detection of the online recoil pressure on the safety valve 8 in the above step is as follows:

the method comprises the steps of opening a first valve 4, closing a second valve 11, providing a detection medium through a medium storage unit, when a safety valve 8 to be detected returns to a seat, if a first pressure detection unit detects that the pressure in a cavity 9 is a second preset pressure, controlling to close the first valve 4 by a controller, detecting the sealing performance of sealing points of a pipeline and parts between the medium storage unit and the safety valve 8 and a pipeline and parts between the cavity 9 and a connecting pipeline of an outlet of the second valve 11, and specifically detecting the sealing performance of the sealing points of a first quick connector 3, the first valve 4, a first ball valve 5, a pressure sensor 6, a second quick connector 7, the second valve 11 and a gasket 21, wherein if the second preset pressure is not changed within a second preset time, a sealing test is qualified, and if the second preset pressure is not changed within a second preset time, the sealing test is not qualified.

Preferably, the second predetermined pressure is 0.9 times the kick-off pressure (1 + ± 0.10%) KPa and the second predetermined time is 3 to 10 minutes. Specifically, the second preset time in this embodiment is 5 minutes.

Preferably, the method further comprises the following steps when the safety valve 8 is subjected to a seal test detection at the time of on-line recoil pressure and the detection result is not qualified:

if particles or impurities exist on a sealing surface between the valve core and the valve seat of the safety valve 8, purging the sealing surface between the valve core and the valve seat of the safety valve 8 at least twice through nitrogen, performing online recoil pressure sealing test detection on the safety valve 8 by using the same method, and if the sealing test is unqualified, detaching the safety valve 8, repairing or replacing corresponding parts, and then performing sealing test detection on the safety valve online detection system again. Specifically, in this embodiment, the sealing surface between the valve element and the valve seat of the safety valve 8 is purged 2 to 3 times with nitrogen gas.

An outline of an online detection system of the method for online detecting the tripping pressure and the seal test pressure of the safety valve 8 in the embodiment

1. The constituent elements are represented by the following symbols:

p1 is defined as a check tripping pressure value of the safety valve 8, P2 is defined as a sealing test pressure value which is 0.9 times the tripping pressure value (assuming that the tripping pressure of the safety valve 8 to be detected is greater than 500 KPa), P3 and P4 are respectively actual measurement pressure values of two pressure sensors 6 of the second pressure detection unit, specifically, the two pressure sensors 6 are remote transmission pressure transmitters, P5 is an actual tripping pressure value of a pressure switch 28 of the second pressure detection unit, the pressure unit is KPa, V1 is a first valve 4, V2 is a second valve 11, n is a high-pressure nitrogen cylinder 1, V3 is a pressure reducing valve 2, V4 is a first ball valve 5, sv safety valve 8, and m is a cavity 9.

2. The safety valve online detection system is summarized as follows:

the safety valve online detection system in the embodiment has the functions of data acquisition, process control, display, recording and the like, and centralized display, operation and management. The hardware control unit adopts Siemens 300 series PLC module, which mainly comprises power supply, CPU, analog output module, communication module (TCP/IP) and touch screen display. The device can provide a DC24V power supply, has the input and output functions of 4-20mA signals of a two-wire instrument, connects P3, P4, V1 and V2 into a PLC module, controls the process that P3 and P4 convert detected pressure signals into 4-20mA signals to be input into a CPU for operation, and outputs the operation result of the CPU to control a V1 valve and a V2 valve so as to meet the control requirement.

The safety valve on-line detection system comprises: the control unit applies Siemens STEP 7V 5.5 programming software to write a program to establish a PID controller, the controller sets automatic and manual modes, P1 is defined as a safety valve 8 test starting and jumping pressure value, P2 is a control target value (sealing test pressure value), P3 and P4 are pressure measurement values, P5 is an actual starting and jumping pressure value, and V1 and V2 are controlled objects.

The on-line detection system of the safety valve uses Siemens 300PLC programming software to write a program to realize automatic control, firstly, a PID controller is established, the controller sets automatic and manual modes, P2 is a control target value (a sealing test pressure value), P1 is defined as a safety valve 8 verification tripping pressure value 185KPa, P2 is a sealing test pressure value, P3 and P4 are pressure measurement values, P5 is an actual tripping pressure value, namely a tripping pressure indicating switch, and V1 and V2 are controlled objects (provided with reliable pressure control and regulation devices or overpressure alarm devices).

3. Detecting the starting pressure of the safety valve 8 to be detected: starting to introduce nitrogen, putting the V1 and V2 regulating valves into an automatic mode, adjusting the V1 valve of the controlled object by the PID controller through operation, and ending the test when the measured pressure P3= P1 (1 +/-2%), P4= P1 (1 +/-2%), the safety valve 8 jumps, and the starting pressure indicator lamp is on; p3 and P4 are pressure measurement values P1 (1 +/-2%) (because P1>500 KPa), and the test result is qualified (note that P1 (1 +/-2%) is a qualified range for detecting the tripping pressure or the setting pressure of the safety valve 8).

4. Wait to examine 8 seal test pressure detections of relief valve: after the jump starting test is qualified, the V1 and V2 valve controllers are put into an automatic mode, the PID controller is used for regulating the controlled objects V1 and V2 through operation, and in combination with the regulation of PID parameters, because P1>300KPa, when the measured pressure P3>0.9 185KPa (1 +/-0.10%), P4>0.9 185KPa (1 +/-0.10%), the controller is used for regulating the pressure relief of the V2 valve, when the measured pressure P3<0.9 × 185KPa (1 +/-0.10%), P4<0.9 × 185KPa (1 +/-0.10%), the controller is used for regulating the V1 valve to inflate until the pressure control range of the P3 and the P4 is infinitely close to 0.9 × 185KPa (1 +/-0.10%), making the detection system go to a steady state with an error range of +/-0.10% 185, when 0.9 × 185kpa (1 + ± 0.10%) = P3 and P4=0.9 × 185kpa (1 + ± 0.10%), the controller closes the V1 and V2 valves to 0%, the mode is adjusted to a manual mode, the sealing test is started, after T time, for example, 5 minutes, if 0.9 × 185kpa (1 + ± 0.10%) = P3 and P4=0.9 × 185kpa (1 + ± 0.10%), continuously observing for 1 minute, the pressure value is unchanged, the sealing test of the safety valve 8 is qualified, and the sealing test is ended; if the time T is 5 minutes, the time T is continuously observed for 1 minute, the P3/P4 slowly and continuously descends, the sealing is possibly not tight, if the P3/P4 descends rapidly, the seat does not return or the jam or the dislocation occurs, the detection is stopped, and the detection is carried out again after the safety valve 8 is disassembled and repaired.

The safety valve online detection system and the detection method in the embodiment realize online detection of the sealing test pressure of the safety valve 8, and can detect flammable, explosive, toxic and harmful gas and a medium containing particles or impurities in fluid by using the additional nitrogen as a test medium, so as to detect the sealing test pressure value of the safety valve 8 online.

In the prior art, the safety valve 8 online detector has certain disturbance influence on the fluid in the pressure container 18 when the safety valve is safely jumped and returned to the seat, namely the fluid in the pressure container 18 has disturbance phenomenon which is mainly reflected in the fluctuation of liquid level and pressure, which brings trouble to the stable operation and adjustment of the production process, is not beneficial to safe and stable production and can bring potential safety risk to field detection personnel. This problem can not appear in the 8 on-line measuring of relief valve of this embodiment, and this embodiment carries out on-line measuring to relief valve 8, uses plus nitrogen gas as the test medium, and is irrelevant with 18 media with pressure vessel, and the fluid does not have the disturbance phenomenon in pressure vessel 18, is favorable to the steady operation regulation of production technology, is favorable to the safety and stability production, has guaranteed on-the-spot measuring personnel safety.

the method is characterized in that online emergency treatment is carried out on the problem of leakage caused by particles or impurities on the sealing surface of the safety valve 8 in service pressure vessel 18 equipment operation, and non-stop online starting pressure and sealing pressure detection is carried out on the safety valve 8 which is applied for long-period operation for more than one year, so that the requirements of relevant laws and regulations are met, and the requirements of relevant departments on at least one verification of the safety valve 8 in use per year are met. The safety valve 8 is subjected to online detection, so that the links of disassembly, transportation, hoisting and reloading are reduced, the detection time can be shortened, and the cost can be saved.

When the safety valve 8 is subjected to off-line cold state verification at normal temperature and normal pressure, the following field practical problems can be solved by using the safety valve on-line detection system:

(1) in order to save large overhaul time, before the large overhaul is stopped, the safety valve 8 which does not need to be overhauled is screened out for online detection, particularly the safety valve 8 with large caliber and high installation position is scheduled to be arranged for online detection when the large overhaul is not carried out, so that the time is saved for the large overhaul, and the construction period and the cost of disassembly, hoisting and safety are reduced (taking the caliber of a rectification unit of a certain crystalline silicon 3.6 ten thousand tons/year project at present as more than 80mm, taking the safety valve 8 with a special installation position as an example, auxiliary cost of a crane and the like is saved by at least 30 ten thousand yuan per year through measurement and calculation);

(2) if the tripping pressure of the safety valve 8 after the safety valve 8 is set by the off-line calibration console is changed frequently through the links of transportation, in-place installation and the like, the tripping pressure and the sealing pressure of the safety valve 8 are detected again before the feeding and starting by using the detection system and the method designed by the embodiment;

(3) the valve clack frequency jump or flutter of the safety valve 8 caused by too large spring stiffness of the safety valve 8 is detected on line by starting the jump and sealing the safety valve 8 after a spring with proper stiffness is used on site; or the regulating ring of the safety valve 8 is improperly adjusted, so that the valve clack frequency jump or vibration occurs in the safety valve 8 due to overhigh recoil pressure, and after the position of the regulating ring is readjusted, the start jump and the sealing detection are performed on line again.

The safety valve online detection system and the detection method in the embodiment have high detection accuracy, and error factors are reduced to the minimum. The detection accuracy is improved by selecting an instrument with higher precision grade, reasonably calibrating the detector and the like.

The pressure sensor 6 and the pressure switch 28 are selected and designed, so that the on-site display can be realized, the remote transmission can be realized, the PLC automatic control system can be accessed, the starting pressure is set within the allowable deviation, and the acousto-optic warning is carried out, so that the visual perception and the auditory perception are realized; and the loop test and the simulation joint debugging of the detection system are completed before the formal commissioning, so that the potential safety hazards that the safety valve 8 is not returned to the seat after being opened and the medium is excessively lost and the like due to excessive pulling of the safety valve 8 can be safely and effectively avoided, the working condition is not disturbed in the detection process, and the safety of field detection work and inspection personnel is ensured.

It will be understood that the above embodiments are merely exemplary embodiments taken to illustrate the principles of the present invention, which is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. An online safety valve detection system, comprising:

a medium storage unit for storing a medium for safety valve detection;

2. The safety valve online detection system according to claim 1,

the medium storage unit includes: the holding vessel, the relief pressure valve of being connected with the holding vessel, the holding vessel is connected with the cavity, and the holding vessel is used for storing the relief valve and detects and use the medium, and the relief pressure valve sets up on the pipeline between holding vessel and cavity, and is located first valve upper reaches, and the relief pressure valve is used for the required pressure when the relief valve of being convenient for detects to the gaseous decompression of holding vessel.

3. The safety valve on-line detection system according to claim 1, wherein the first pressure detection unit includes: the pressure detection module is used for detecting the pressure in the cavity and sending the pressure to the control unit, the first display module is used for displaying the pressure value received by the control unit, and when the pressure in the cavity exceeds the alarm pressure value, the control unit controls the alarm module to send out an alarm instruction and automatically adjusts the opening of the second valve to release the pressure.

4. The safety valve online detection system according to any one of claims 1 to 3, further comprising: and the second pressure detection unit is arranged on the conveying pipeline between the first valve and the cavity and is used for detecting and displaying the pressure in the input pipeline.

5. The safety valve on-line detection system according to claim 4, wherein a first quick coupling is provided on the input line between the first valve and the medium storage unit;

6. The safety valve online detection system according to claims 1 to 3 and 5, further comprising: a mounting bracket for supporting the mounting cavity, the mounting bracket comprising: the cavity further comprises a base arranged below the cavity body, and the three-jaw clamp is connected with the base.

7. An inspection method using the safety valve on-line inspection system according to any one of claims 1 to 6, comprising the steps of:

8. The inspection method of an online inspection system for safety valves according to claim 7, wherein the installation position of the cavity is a position where a rupture disk with a gripper or a flange nipple is installed between the safety valve to be inspected and the root valve.

9. The method for detecting the safety valve online detection system according to claim 7, wherein the method for performing the seal test detection of the online tripping-back pressure on the safety valve comprises the following specific steps:

10. The method for detecting the safety valve online detection system according to claim 9, wherein in the step of performing the sealing test detection of the online tripping and falling pressure on the safety valve, if the first pressure detection unit detects that the pressure in the cavity is greater than the first preset pressure, the control unit opens the second valve to perform pressure relief until the first pressure detection unit detects that the pressure in the cavity is the first preset pressure, and then automatically closes the second valve;

11. The method for detecting the safety valve online detection system according to claim 7, wherein the steps of performing the seal test detection of the online recoil pressure of the safety valve are as follows:

the method comprises the steps of opening a first valve, closing a second valve, providing a detection medium through a medium storage unit, when a safety valve to be detected returns to a seat, if the first pressure detection unit detects that the pressure in a cavity is a second preset pressure, controlling to close the first valve by a controller, detecting the sealing performance of sealing points of a pipeline and a part between the medium storage unit and the safety valve, a pipeline and a part between the cavity and a connecting pipeline of an outlet of the second valve, and if the second preset pressure is unchanged within second preset time, the sealing test is qualified, and otherwise, the sealing test is unqualified.

12. The method for testing the safety valve online detection system according to claim 11, wherein the method further comprises the following steps if the test result is not qualified after the seal test of the safety valve during online recoil pressure is performed on the safety valve:

if the sealing surface between the valve core and the valve seat of the safety valve has particles or impurities, purging the sealing surface between the valve core and the valve seat of the safety valve at least twice through nitrogen, and performing sealing test detection of online recoil pressure on the safety valve by using the same method, if the sealing test is unqualified, detaching the safety valve, repairing or replacing corresponding parts, and then performing sealing test detection of the safety valve online detection system again.