CN115931342B

CN115931342B - Comprehensive test bed and comprehensive test method for safety valve

Info

Publication number: CN115931342B
Application number: CN202310243706.XA
Authority: CN
Inventors: 何明; 孙瑞亮; 李豪; 刘志龙; 朱全琛; 陶波
Original assignee: HEFEI GENERAL ENVIRONMENT CONTROL TECHNOLOGY CO LTD; Hefei General Machinery Research Institute Co Ltd
Current assignee: HEFEI GENERAL ENVIRONMENT CONTROL TECHNOLOGY CO LTD; Hefei General Machinery Research Institute Co Ltd
Priority date: 2023-03-15
Filing date: 2023-03-15
Publication date: 2023-05-16
Anticipated expiration: 2043-03-15
Also published as: CN115931342A

Abstract

The invention discloses a comprehensive test bed and a comprehensive test method for a safety valve, which relate to the technical field of safety valve tests and comprise the following steps: the device comprises a pressurizing device, a first pressure container, a temperature regulating device, a gas path regulating device, a second pressure container, a safety valve test branch, a safety valve to be tested and a numerical control center which are sequentially connected along the gas transmission direction; the safety valve to be tested is placed in the environment adjusting bin, and different working environment temperatures are provided for the safety valve to be tested; the safety valve to be tested is provided with a spraying device and an image acquisition device, the spraying device is used for spraying leakage measuring liquid to the safety valve to be tested, and the image acquisition device is used for acquiring surface images of the safety valve to be tested. The invention can simulate different working temperatures and different working pressures of the safety valve and also simulate different working environments of the safety valve, so that various tests can be carried out on the safety valve to be tested under different working temperatures, different working pressures and different working environments, and the working performance of the safety valve to be tested can be comprehensively tested.

Description

Comprehensive test bed and comprehensive test method for safety valve

Technical Field

The invention relates to the technical field of safety valve testing, in particular to a comprehensive test bed and a comprehensive test method for a safety valve.

Background

With the vigorous development of rail transit, high-speed railway trains and urban rail trains can work under various external conditions such as different temperatures, humidity and the like, wherein a wind source device for providing clean high-pressure aerodynamic force for a braking system is core equipment related to safety.

The compressor in the wind source device is used for compressing atmospheric air, the high-pressure air which is purified later is stored in the high-pressure air storage tank, and the safety valve is used for adjusting the air pressure in the air storage tank to be within a safety air pressure threshold value.

The safety valve is an automatic relief valve, its opening and closing member is in normally closed state under the action of external force, when the pressure of medium in the equipment or pipeline is raised, and exceeds the defined safety value, the valve is automatically opened, and the rated quantity of medium is discharged to the outside of system so as to prevent the pressure of medium in the pipeline or equipment from exceeding the defined safety value, and when the pressure of medium in the pipeline or equipment is recovered to normal, the valve is closed again and the medium is prevented from continuously flowing out.

Therefore, it is necessary to perform a test for the safety valve to test the operation performance of the safety valve.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides the comprehensive test bed for the safety valve, which can simulate different working temperatures and different working pressures of the safety valve and can simulate different working environments of the safety valve, so that various tests can be carried out on the safety valve to be tested under different working temperatures, different working pressures and different working environments, and the working performance of the safety valve to be tested can be comprehensively tested.

In order to achieve the above purpose, the present invention adopts the following technical scheme, including:

a comprehensive test stand for a safety valve, the comprehensive test stand comprising: the pressure boosting device, the first pressure container, the temperature regulating device, the gas path regulating device, the second pressure container, the safety valve test branch and the safety valve to be tested are sequentially connected along the gas transmission direction;

the pressurizing device is used for pressurizing the gas and inputting the pressurized gas into the first pressure container; the temperature regulating device is used for regulating the temperature of the gas flowing into the second pressure container; the gas path adjusting device is used for adjusting the flow rate of the gas flowing into the second pressure container; the second pressure container is used for storing gas with set pressure and set temperature and is used for testing the safety valve to be tested; the safety valve to be tested is connected with the second pressure container through a safety valve test branch;

the second pressure container is also connected with a discharge device, and the discharge device is used for discharging the gas in the second pressure container;

the first pressure container and the second pressure container are respectively provided with a temperature sensor and a pressure sensor for collecting the gas temperature and the gas pressure in the pressure containers;

The comprehensive test bed also comprises an environment adjusting bin, wherein the safety valve to be tested is placed in the environment adjusting bin, and the environment adjusting bin is used for providing different working environment temperatures for the safety valve to be tested;

the comprehensive test bed also comprises a spraying device and an image acquisition device, wherein the spraying device is used for spraying leakage measurement liquid to the safety valve to be tested, and the image acquisition device is used for acquiring surface images of the safety valve to be tested;

the comprehensive test bed also comprises a numerical control center, wherein the numerical control center is connected with each sensor and is used for receiving the acquired data of each sensor; the numerical control center is also connected with each device and used for controlling each device.

Preferably, the supercharging device comprises a high-pressure gas path and a normal-pressure gas path which are connected in parallel, the high-pressure gas path is provided with a first stop valve and a booster pump, and the normal-pressure gas path is provided with a second stop valve; the discharging device comprises a second one-way valve, a third regulating valve and a muffler which are sequentially connected along the gas transmission direction.

Preferably, the temperature adjusting means includes a cooler and a heater.

Preferably, the gas path adjusting device comprises a third stop valve, a first one-way valve and an adjusting valve component which are sequentially connected along the gas transmission direction; the regulating valve assembly comprises a first regulating valve and a second regulating valve which are connected in parallel; the first regulating valve and the second regulating valve are both used for regulating the air quantity, and the regulating precision of the first regulating valve is smaller than that of the second regulating valve.

Preferably, the spraying device comprises a liquid storage tank, a liquid pump, a third pressure sensor and a spraying head which are sequentially connected along the liquid flow direction; the liquid storage tank is used for storing leakage measuring liquid, the liquid pump is used for adjusting hydraulic pressure, the third pressure sensor is used for measuring hydraulic pressure, and the spray header is located above the safety valve to be tested and used for spraying the safety valve to be tested.

Preferably, the camera of the image acquisition device is arranged at the side of the safety valve to be detected, and performs rotary displacement along the surface of the safety valve to be detected, so as to acquire the surface images of all angles of the safety valve to be detected.

Preferably, the comprehensive test bench further comprises a gas purifying device for purifying the gas inputted into the first pressure vessel; the purification treatment comprises dust removal, oil removal and water removal; the gas purification device comprises a dust remover, an oil remover and a water remover which are sequentially connected along the gas transmission direction.

The invention also provides a comprehensive test method of the comprehensive test bed for the safety valve, which utilizes the comprehensive test bed to carry out the air tightness test on the safety valve to be tested, and the specific method is as follows:

s11, mounting a safety valve to be tested on a safety valve test branch of a comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center to serve as calibration parameters;

S12, connecting an input end of a pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device to input high-pressure air into the first pressure container by the numerical control center;

s13, the numerical control center opens the gas path regulating device, inputs high-pressure gas stored in the first pressure container into the second pressure container and the safety valve test branch, and closes the gas path regulating device after regulating the gas pressure in the second pressure container to reach the set pressure by controlling the gas path regulating device; the set pressure is A% of the factory setting pressure of the safety valve to be tested;

s14, the numerical control center opens a spraying device, sprays leakage measuring liquid to the safety valve to be tested, and closes the spraying device after the surface of the safety valve to be tested is soaked in the leakage measuring liquid;

s15, the numerical control center opens an image acquisition device, acquires the surface image of the safety valve to be detected at the current moment, namely at the moment T1, and sends the surface image of the safety valve to be detected at the moment T1 to the numerical control center;

s16, after the interval delta T, acquiring a surface image of the safety valve to be detected at the current moment, namely at the moment T2, and sending the surface image of the safety valve to be detected at the moment T2 to a numerical control center; t2=t1+Δt;

s17, the numerical control center performs contrast analysis on the surface images of the safety valve to be tested at the front moment and the rear moment according to the surface images of the safety valve to be tested at the moment T1 and the moment T2:

Counting the number of bubbles in the surface images at the front and rear moments, and the positions and the circumference lengths of the bubbles, wherein if the number of bubbles in the surface image at the moment T2 is larger than the number of bubbles in the surface image at the moment T1, or the circumference length of a certain bubble in the surface image at the moment T2 is larger than the circumference length of a bubble at the corresponding position in the surface image at the moment T1, the safety valve to be tested is indicated to leak under the factory setting pressure of A%; otherwise, the safety valve to be tested is not leaked under the factory setting pressure of A%;

s18, the numerical control center controls the gas circuit adjusting device to boost the pressure of the second pressure container, so that the gas pressure in the second pressure container is increased by delta a% each time until the pressure is increased to the factory setting pressure, and the tightness of the safety valve to be tested under the factory setting pressure of (A+delta a), (A+2delta a), (A+3delta a), (A+3 delta a), and the factory setting pressure is tested respectively according to the mode of the steps S14-S17;

s19, controlling a temperature regulating device by the numerical control center, regulating the gas temperature in the second pressure container, and respectively testing the air tightness of the safety valve to be tested at different gas temperatures according to the mode of the steps S14-S18.

Preferably, a comprehensive test bed is utilized to sequentially perform a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse withstand voltage test and a reliability test on the safety valve to be tested, and the specific method is as follows:

s21, mounting a safety valve to be tested on a safety valve test branch of the comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center to serve as calibration parameters;

s22, connecting an input end of the pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device by the numerical control center to input high-pressure air into the first pressure container;

s23, the gas path adjusting device is opened by the numerical control center, and high-pressure gas stored in the first pressure container is input into the second pressure container and the safety valve test branch;

s24, performing a discharge pressure test on the safety valve to be tested:

s241, the numerical control center controls the gas path regulating device to pressurize the second pressure container, and after the gas pressure in the second pressure container reaches the set pressure, the gas path regulating device is closed; the set pressure is A% of the factory setting pressure of the safety valve to be tested;

s242, the numerical control center controls the gas circuit adjusting device to continuously boost the second pressure container, the boosting speed is smaller than that of the step S241, the numerical control center judges the pressure drop in the second pressure container in real time according to the acquired data of the pressure sensor on the second pressure container, if the pressure drop rate exceeds a set threshold, the gas pressure in the second pressure container when the first pressure drop rate exceeds the set threshold is recorded, and the gas pressure in the second pressure container at the moment is used as the actual setting pressure of the safety valve to be tested; otherwise, continuing to boost until the first pressure drop rate exceeds the set threshold value, and obtaining the actual setting pressure of the safety valve to be tested;

S243, after the first pressure drop rate exceeds the set threshold, the numerical control center controls the gas circuit regulating device to continuously boost the second pressure container, the boosting speed is smaller than that of the step S241, the numerical control center judges the pressure drop in the second pressure container in real time according to the acquired data of the pressure sensor on the second pressure container, if the pressure drop rate exceeds the set threshold, the gas pressure in the second pressure container when the second pressure drop rate exceeds the set threshold is recorded, and the gas pressure in the second pressure container at the moment is used as the actual discharge pressure of the safety valve to be tested; otherwise, continuing to boost until the second pressure drop rate exceeds the set threshold value, and obtaining the actual discharge pressure of the safety valve to be tested;

if the discharge pressure test of the safety valve to be tested is qualified, namely the actual discharge pressure and the actual setting pressure of the safety valve to be tested meet the error range of the calibration parameters, performing the next test, otherwise, terminating the test and reporting the reason for terminating the test;

s25, carrying out pressure maintaining test on the safety valve to be tested:

s251, the numerical control center controls the gas path adjusting device, and after the gas pressure in the second pressure container reaches the set pressure, the gas path adjusting device is closed; the set pressure is A% of the actual setting pressure of the safety valve to be tested;

S252, the numerical control center judges the pressure drop in the second pressure container in real time according to the acquired data of the pressure sensor on the second pressure container, and if the pressure drop rate exceeds a set threshold or the pressure drop exceeds a set value in a set time, the numerical control center indicates that the safety valve to be tested does not maintain pressure under the actual setting pressure of A%; otherwise, the safety valve to be tested is kept under the factory setting pressure of A%;

s253, the numerical control center controls the gas circuit adjusting device to boost the pressure of the second pressure container, so that the gas pressure in the second pressure container is increased by delta a% each time until the pressure is increased to the actual setting pressure, and the pressure maintaining performance of the safety valve to be tested under the actual setting pressure of (A+delta a)% and the actual setting pressure of (A+2 delta a)% and the actual setting pressure is tested respectively according to the mode of the step S252;

if the pressure maintaining test of the safety valve to be tested is qualified, namely the safety valve to be tested has pressure maintaining property, performing the next test, otherwise, terminating the test and reporting the reason for terminating the test;

s26, carrying out a seat returning pressure test on the safety valve to be tested:

s261, controlling the gas path regulating device by the numerical control center, and closing the gas path regulating device after the gas pressure in the second pressure container reaches the set pressure; the set pressure is the actual discharge pressure of the safety valve to be tested;

S262, the numerical control center opens the discharge device, discharges the gas in the second pressure container by using the discharge device, namely, reduces the pressure, and judges the pressure drop in the second pressure container in real time according to the acquired data of the pressure sensor on the second pressure container until the pressure of the gas in the second pressure container is kept unchanged, namely, the pressure drop is 0, and records the pressure of the gas in the second pressure container when the pressure drop is 0 at the moment, and the pressure is taken as the actual seat returning pressure of the safety valve to be tested;

if the back seat pressure test of the safety valve to be tested is qualified, namely the actual back seat pressure of the safety valve to be tested meets the error range of the calibration parameters, performing the next test, otherwise, terminating the test and reporting the reason for terminating the test;

s27, performing pulse withstand voltage test on the safety valve to be tested:

s271, the numerical control center controls the gas path adjusting device, and after the gas pressure in the second pressure container reaches the set pressure, the gas path adjusting device is closed; the set pressure is the actual setting pressure of the safety valve to be tested;

s272, the numerical control center opens a discharge device, and discharges the gas in the second pressure container by using the discharge device until the gas pressure in the second pressure container is discharged to zero;

S273, cycling the steps S271-S272, and judging whether the safety valve to be tested is damaged or not after cycling for a plurality of times, wherein the judging mode is as follows:

according to the modes of the steps S24 and S26, carrying out a discharge pressure test and a seat returning pressure test on the safety valve to be tested again to obtain the setting pressure, the discharge pressure and the seat returning pressure of the safety valve to be tested after the pulse withstand voltage test at the moment, judging whether the setting pressure, the discharge pressure and the seat returning pressure at the moment are in the error range of the calibration parameters, and if the setting pressure, the discharge pressure and the seat returning pressure are all in the error range of the calibration parameters, indicating that the safety valve to be tested has the pulse withstand voltage; otherwise, the safety valve to be tested does not have pulse pressure resistance;

if the pulse withstand voltage test of the safety valve to be tested is qualified, namely the safety valve to be tested has pulse withstand voltage, performing the next test, otherwise, terminating the test and reporting the reason for terminating the test;

s28, performing reliability test on the safety valve to be tested:

s281, controlling a temperature regulating device by a numerical control center to regulate the temperature of the gas in the second pressure container;

s282, according to the mode of the steps S24-S27, carrying out discharge pressure test, pressure maintaining test, seat returning pressure test and pulse pressure resisting test on the safety valve to be tested in sequence at different gas temperatures, and testing the setting pressure, the discharge pressure, the pressure maintaining performance, the seat returning pressure and the pulse pressure resisting performance of the safety valve to be tested at different gas temperatures;

And if the test of the safety valve to be tested at different gas temperatures is qualified, ending the test, and if the test of the safety valve to be tested at a certain gas temperature is not qualified, ending the test and reporting the reason for ending the test.

Preferably, the comprehensive test bed is used for carrying out working environment test on the safety valve to be tested, and the specific method is as follows:

s31, mounting a safety valve to be tested on a safety valve test branch of the comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center to serve as calibration parameters;

s32, connecting an input end of the pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device to input high-pressure air into the first pressure container by the numerical control center;

s33, the numerical control center opens the gas path adjusting device, and inputs the high-pressure gas stored in the first pressure container into the second pressure container and the safety valve test branch;

s34, controlling an environment adjusting bin by a numerical control center, and adjusting the working environment temperature of the safety valve to be tested;

s35, respectively performing various tests on the safety valve to be tested at various working environment temperatures to test the working performance of the safety valve to be tested at different working environment temperatures

The invention has the advantages that:

(1) The invention can simulate different working temperatures and different working pressures of the safety valve and also simulate different working environments of the safety valve, so that various tests including an air tightness test, a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse withstand voltage test, a reliability test and a working environment test can be carried out on the safety valve to be tested under different working temperatures, different working pressures and different working environments, and the working performance of the safety valve to be tested can be comprehensively tested.

(2) According to the invention, after the pressurizing device is utilized to charge scalar air quantity into the first pressure container at one time, test air quantity is provided for the whole comprehensive test bed. Because the second pressure container is a small pressure container, the multi-time deflation and inflation are involved, a certain amount of high-pressure standard is reserved in the large pressure container, namely the first pressure container, and the small pressure container can be continuously inflated subsequently, so that frequent operation of a booster pump compressor is avoided.

(3) The invention utilizes the cooler and the heater in the temperature adjusting device to enable the comprehensive test bed to simulate different working temperatures so as to finish the working performance test of the safety valve to be tested at different working temperatures.

(4) According to the invention, the gas is input into the second pressure container by using the gas circuit adjusting device, the first adjusting valve is used for adjusting the gas quantity roughly, and the second adjusting valve is used for adjusting the gas quantity finely, so that the accurate adjustment of the gas pressure in the second pressure container is realized, different working pressures can be simulated by the comprehensive test bed, and the working performance test of the safety valve to be tested can be conveniently finished under different working pressures.

(5) According to the invention, the gas is purified by the gas purifying device, so that the influence of dust in the gas is reduced, the service life of the comprehensive test stand is prolonged, and the measurement error of the working performance parameters is reduced.

(6) The invention can automatically complete the air tightness test of the safety valve to be tested based on the spraying device, the image acquisition device and the target identification.

(7) The invention provides a comprehensive test method based on a comprehensive test bed, which comprises an air tightness test, a discharge pressure test, a pressure maintaining test, a back seat pressure test, a pulse withstand voltage test, a reliability test and a working environment test, wherein test items are comprehensive, and the comprehensive test of the working performance of a safety valve to be tested is ensured.

Drawings

FIG. 1 is an overall schematic view of a comprehensive test stand for a safety valve according to the present invention.

Reference numerals illustrate:

1-first stop valve, 2-booster pump, 3-second stop valve, 4-dust remover, 5-deoiler, 6-water remover, 7-first pressure vessel, 8-first temperature sensor, 9-first pressure sensor, 10-cooler, 11-heater, 12-third stop valve, 13-first check valve, 14-first governing valve, 15-second governing valve, 16-second pressure vessel, 17-second temperature sensor, 18-second pressure sensor, 19-second check valve, 20-third governing valve, 21-muffler, 22-fifth stop valve, 23-environmental conditioning bin, 24-second to-be-tested relief valve, 25-fourth stop valve, 26-first to-be-tested relief valve, 27-camera, 29-liquid pump, 30-third pressure sensor, 31 shower head, 32-numerical control center.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

As shown in fig. 1, a comprehensive test stand for a safety valve of the present invention includes: the system comprises a supercharging device, a gas purifying device, a first pressure container 7, a temperature adjusting device, a gas path adjusting device, a second pressure container 16, a discharging device, a safety valve test branch, a safety valve to be tested, an environment adjusting bin 23, a spraying device, an image collecting device, a data collecting circuit, a device control circuit and a data processing and controlling center, namely a numerical control center 32.

The supercharging device comprises a high-pressure gas circuit and a normal-pressure gas circuit which are connected in parallel, a first stop valve 1 and a booster pump 2 are arranged on the high-pressure gas circuit, a second stop valve 3 is arranged on the normal-pressure gas circuit, the parallel input end of the high-pressure gas circuit and the normal-pressure gas circuit is used for inputting gas, and the parallel output end of the high-pressure gas circuit and the normal-pressure gas circuit is connected with the input end of the gas purifying device; the high-pressure gas path is used for pressurizing gas.

The gas purifying device comprises a dust remover 4, an oil remover 5 and a water remover 6 which are sequentially connected along the gas transmission direction; the gas purification device is used for purifying gas and comprises dust removal, oil removal and water removal.

The output end of the gas purifying device, namely the output end of the dehydrator 6, is connected with the input end of the first pressure vessel 7; the output end of the first pressure container 7 is connected with the input end of the temperature regulating device; the first pressure container 7 is provided with a first temperature sensor 8 and a first pressure sensor 9 for respectively measuring the gas temperature and the gas pressure in the first pressure container 7; the first pressure container 7 is used for providing test gas for the whole test bed after being filled with the calibration gas quantity at one time.

The temperature regulating device comprises a cooler 10 and a heater 11 which are sequentially connected along the gas transmission direction; the temperature adjusting device is used for adjusting the gas temperature, namely adjusting the inlet temperature of the safety valve to be tested, supporting the test bed to simulate different working temperatures, and completing the working performance test of the safety valve to be tested at the simulated different working temperatures; the output end of the temperature adjusting device, namely the output end of the heater 11, is connected with the input end of the air path adjusting device.

The gas path regulating device comprises a third stop valve 12, a first one-way valve 13 and a regulating valve component which are sequentially connected along the gas transmission direction; the regulating valve assembly comprises a first regulating valve 14 and a second regulating valve 15 which are connected in parallel; the input end of the first check valve 13 is connected with the output end of the third stop valve 12, the output end of the first check valve 13 is connected with the input end of the regulating valve assembly, namely the parallel input ends of the first regulating valve 14 and the second regulating valve 15, and the output end of the regulating valve assembly, namely the parallel output ends of the first regulating valve 14 and the second regulating valve 15, is connected with the output end of the second pressure container 16; the first regulating valve 14 is used for coarse gas volume adjustment, and the second regulating valve 15 is used for fine gas volume adjustment. The gas circuit adjusting device is used for adjusting the working pressure of the safety valve to be tested, supporting the test bed to simulate different pressure conditions, and completing the working performance test of the safety valve to be tested under the simulated different pressure conditions.

The first output of the second pressure vessel 16 is connected to the input of the discharge means; the discharging device comprises a second one-way valve 19, a third regulating valve 20 and a muffler 21 which are sequentially connected along the gas transmission direction; the output end of the discharging device is used for discharging gas outwards.

A second output end of the second pressure vessel 16 is connected with an input end of the safety valve test branch; the second pressure container 16 is provided with a second temperature sensor 17 and a second pressure sensor 18 for measuring the gas temperature and the gas pressure in the second pressure container 16 respectively; the second pressure vessel 16 is used to provide test gas meeting temperature and pressure conditions for a single type of test. The tail end, namely the output end, of the safety valve test branch is connected with the safety valve to be tested.

In the invention, the safety valve to be tested is placed in an environment adjusting bin 23, and the environment adjusting bin 23 is used for providing different working environment temperatures for the safety valve to be tested; or the safety valve to be tested is provided with a spraying device and an image acquisition device, the spraying device is used for spraying leakage measuring liquid to the safety valve to be tested, and the image acquisition device is used for acquiring surface images of the safety valve to be tested; alternatively, the safety valve to be tested is placed in the environment adjusting bin 23 and is provided with a spraying device and an image acquisition device.

In this embodiment, considering the size of the comprehensive test bench, because the occupied space of the spraying device and the image acquisition device is larger, the spraying device and the image acquisition device are not arranged in the environment adjustment bin, but are respectively and independently arranged, and as shown in fig. 1, the comprehensive test bench provides two safety valve test branches, namely a first safety valve test branch and a second safety valve test branch, for simultaneously testing two safety valves to be tested in different projects.

A fourth stop valve 25 is arranged on the first safety valve test branch, and the tail output end of the first safety valve test branch is connected with a first safety valve 26 to be tested; the first safety valve 26 to be tested is provided with a spraying device and an image acquisition device. The first safety valve test branch is used for performing an air tightness test, a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse withstand voltage test and a reliability test of the first safety valve 26 to be tested.

A fifth stop valve 22 is arranged on the second safety valve test branch, and the output end of the second safety valve test branch is connected with a second safety valve 24 to be tested; the second to-be-tested safety valve 24 is configured with an environment adjusting bin 23, that is, the second to-be-tested safety valve 24 is located in the environment adjusting bin 23, the environment adjusting bin 23 provides the working environment temperature of-40 ℃ to +65 ℃ for the second to-be-tested safety valve 24, is used for simulating extreme working environments of burning sun and severe cold, and can test the working performance of the second to-be-tested safety valve 24 under the extreme working environments. The second safety valve test branch is used for performing a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse withstand voltage test and a reliability test of the second safety valve 24 to be tested under an extreme working environment.

In the present embodiment, when the air tightness test, the discharge pressure test, the holding pressure test, the recoil pressure test, the impulse withstand voltage test, the reliability test are sequentially performed on the first relief valve 26 to be tested, the fourth shut-off valve 25 is opened and the fifth shut-off valve 22 is closed. When the discharge pressure test, the holding pressure test, the seat returning pressure test, the impulse withstand voltage test, and the reliability test are sequentially performed on the second safety valve 24 to be tested at each operating environment temperature, the fourth shut-off valve 25 is closed and the fifth shut-off valve 22 is opened.

The spraying device comprises a liquid storage tank 28, a liquid pump 29, a third pressure sensor 30 and a spraying head 31 which are sequentially connected along the liquid flow direction; the liquid storage tank 28 is used for storing leakage measuring liquid, the liquid pump 29 is used for adjusting hydraulic pressure, the third pressure sensor 30 is used for measuring hydraulic pressure, and the spray header 31 is located above the safety valve to be tested and is used for spraying the safety valve to be tested. Specifically, the leakage measurement liquid is a solution added with a surfactant component, such as soapy water or the like.

The camera 27 of the image acquisition device is arranged at the side of the safety valve to be detected, and performs rotary displacement along the safety valve to be detected, so as to acquire surface images of all angles of the safety valve to be detected; in particular, the image capture device utilizes a rail mechanism to provide rotational displacement capability for the camera 27.

The data acquisition circuit is used for respectively connecting the first temperature sensor 8, the first pressure sensor 9, the second temperature sensor 17, the second pressure sensor 18 and the third pressure sensor 30 with the numerical control center 32, and the acquired data of each sensor is sent to the numerical control center 32.

The device control circuit is used for respectively connecting the first stop valve 1, the booster pump 2, the second stop valve 3, the dust remover 4, the oil remover 5, the water remover 6, the cooler 10, the heater 11, the third stop valve 12, the first regulating valve 14, the second regulating valve 15, the third regulating valve 20, the fourth stop valve 25, the fifth stop valve 22, the environment regulating bin 23 and the liquid pump 29 with the numerical control center 32, and the numerical control center 32 controls each controlled object.

The comprehensive test bench provided by the invention is used for comprehensively testing the safety valve to be tested, and comprises the following steps: air tightness test, discharge pressure test, pressure maintaining test, back seat pressure test, impulse withstand voltage test, reliability test and working environment test.

In this embodiment, the air tightness test is performed on the first to-be-tested safety valve 26 on the first safety valve test branch by using the comprehensive test bench, and the specific method is as follows:

s11, installing the first safety valve 26 to be tested on a first safety valve test branch of the comprehensive test bench, and inputting factory parameters of the first safety valve 26 to be tested into the numerical control center 32 as calibration parameters, wherein the method comprises the following steps: nominal pressure, operating pressure, trim pressure, discharge pressure, seat back pressure, pressure rating, flow channel diameter, operating environment temperature range. The reservoir 28 is filled with a standard graduated quantity of leak measurement fluid. In the initial state, all valves on the test bed are in a closed state, and all devices are in an unoperated state.

Wherein, nominal pressure refers to: the safety valve body is allowed to bear pressure at maximum, such as PN16, PN25, PN40 and PN64. The working pressure is as follows: the safety valve body can bear normal pressure. Setting pressure means: the preset pressure of the valve clack of the safety valve when the valve clack starts to open under the running condition is the gauge pressure measured at the inlet of the valve, namely the pressure of the opening action of the safety valve, and the safety valve can be opened when the pressure value is reached or exceeded, and the preset pressure is a manually set value, generally 1.05-1.1 times of the highest working pressure, and is a safety value which is larger than the normal working pressure of the equipment and smaller than the design pressure of the equipment. The discharge pressure refers to: the set pressure plus the excess pressure (excess pressure means the pressure increase over the set pressure of the safety valve, usually expressed as a percentage of the set pressure), i.e. the inlet pressure at which the flap reaches the prescribed opening height, the upper limit of the discharge pressure being subject to the requirements of the relevant national standard or regulations. The recoil pressure is: after the safety valve is discharged, the valve clack is pressed against the valve seat again, and the inlet pressure when the medium stops discharging is the back seat pressure, which is an important parameter for representing the use quality of the safety valve. The diameter of the flow channel is as follows: diameter of the smallest cross-sectional area of the flow path from the inlet end of the flap to the sealing surface of the closure member.

S12, connecting the input end of the pressurizing device with an air source, inputting air into the pressurizing device, and if the air source is a high-pressure air source, opening the second stop valve 3 by the numerical control center 32, wherein the first stop valve 1 and the pressurizing pump 2 are in a closed state; if the air source is an atmospheric air source, the numerical control center 32 opens the first stop valve 1 and the booster pump 2, and the second stop valve 3 is in a closed state at the moment; simultaneously, the numerical control center 32 opens the dust remover 4, the oil remover 5 and the water remover 6, high-pressure gas flowing out of the pressurizing device enters the first pressure container 7 after being purified by the gas purifying device, high-pressure gas is input into the first pressure container 7, and at the moment, the third stop valve 12 is in a closed state; in the process of inflating the first pressure container 7, the numerical control center 32 adjusts and controls the second stop valve 3, the first stop valve 1 and the booster pump 2 according to the acquired data of the first pressure container 9 until the gas pressure in the first pressure container 7 reaches the working pressure, and then the gas input to the booster device is stopped, and the high-pressure gas stored in the first pressure container 7 is directly used as a test gas source in the subsequent test.

S13, the nc center 32 opens the third stop valve 12, the first regulating valve 14, and the second regulating valve 15, and in this embodiment, since the first to-be-tested safety valve 26 is subjected to the airtight test, the nc center 32 also opens the fourth stop valve 25, and the fifth stop valve 22 is in a closed state. The high-pressure gas stored in the first pressure container 7 is input into the second pressure container 16 and the first safety valve test branch, meanwhile, the collected data of the second pressure container 18 are received, the opening degrees of the first regulating valve 14 and the second regulating valve 15 are gradually regulated according to the gas pressure in the second pressure container 16 until the gas pressure in the second pressure container 16 reaches 90% of the factory setting pressure, and the gas tightness of the first safety valve 26 to be tested under the condition that the gas pressure is 90% of the factory setting pressure is tested. The numerical control center 32 closes the third stop valve 12, the first regulating valve 14, and the second regulating valve 15.

S14, the numerical control center 32 opens the liquid pump 29, adjusts the pumping speed of the liquid pump 29 until the hydraulic value measured by the third pressure sensor 30 reaches a calibration value, at this time, the leakage measurement liquid stored in the liquid storage tank 28 sprays the first to-be-measured safety valve 26 through the spray header 31, and closes the liquid pump 29 after the surface of the first to-be-measured safety valve 26 is soaked with the leakage measurement liquid.

S15, the numerical control center 32 controls the camera 27 of the image acquisition device to shoot, and performs rotary displacement along the first to-be-detected safety valve 26, acquires surface images of the first to-be-detected safety valve 26 at all angles at the current moment, namely at the moment T1, and sends the surface images to the numerical control center 32; the numerical control center 32 recognizes the surface images of the respective angles, recognizes the bubbles in the surface images of the respective angles, counts the number of bubbles in the surface images of the respective angles at the time T1, and the circle center position and the circumference length of the respective bubbles.

S16, after the interval delta T, collecting the surface images of the first to-be-tested safety valve 26 at all angles at the current moment, namely the moment T2, and counting the number of bubbles in the surface images of all angles at the moment T2, and the circle center position and the circle circumference of each bubble. Where t2=t1+Δt.

S17, the numerical control center 32 performs contrast analysis on the surface images of the same angle at the front and rear moments according to the surface images of the first to-be-detected safety valve 26 at the front and rear moments, namely the moment T1 and the moment T2:

if the number of bubbles in the surface image at the time T2 is increased compared with the number of bubbles in the surface image at the time T1, and the increased number of bubbles exceeds the set threshold, the first to-be-tested safety valve 26 is indicated to leak under 90% factory setting pressure; if the circumference of a certain bubble in the surface image at the time T2 is increased compared with the circumference of a bubble at the corresponding position in the surface image at the time T1, and the increase value of the circumference exceeds the set threshold, the first safety valve 26 to be tested is indicated to leak under 90% factory setting pressure; otherwise, it means that the first relief valve 26 to be tested is not leaking at 90% of the factory setting pressure.

S18, the numerical control center 32 controls the gas circuit adjusting device to boost the pressure of the second pressure container 16, so that the gas pressure in the second pressure container 16 is increased by 2% each time until the pressure is increased to the factory setting pressure, and the tightness of the first safety valve 26 to be tested at 92%, 94%, 96%, 98% and 100% of the factory setting pressure is tested respectively according to the mode of the steps S14-S17.

S19, the numerical control center 32 controls a temperature adjusting device to adjust the gas temperature in the second pressure container 16, and the tightness of the first to-be-tested safety valve 26 is tested at different gas temperatures according to the mode of steps S14-S18.

If the air tightness test of the first safety valve 26 to be tested is qualified, the next test is performed, otherwise, the test is terminated and the reason for the termination of the test is reported.

In this embodiment, the comprehensive test bench is utilized to sequentially perform a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse withstand voltage test and a reliability test on the first safety valve 26 to be tested on the first safety valve test branch, and the specific method is as follows:

s21, installing the first safety valve 26 to be tested on a first safety valve test branch of the comprehensive test bench, and inputting factory parameters of the first safety valve 26 to be tested into the numerical control center 32 as calibration parameters, wherein the method comprises the following steps: nominal pressure, operating pressure, trim pressure, discharge pressure, seat back pressure, pressure rating, flow channel diameter, operating environment temperature range. In the initial state, all valves on the test bed are in a closed state, and all devices are in an unoperated state.

S22, connecting the input end of the pressurizing device with an air source, inputting air to the pressurizing device, simultaneously, opening the air purifying device by the numerical control center 32, purifying the high-pressure air flowing out of the pressurizing device, entering the first pressure container 7, inputting the high-pressure air into the first pressure container 7, stopping inputting the air to the pressurizing device until the air pressure in the first pressure container 7 reaches the working pressure, and directly adopting the high-pressure air stored in the first pressure container 7 as a test air source in a subsequent test.

S23, the nc center 32 opens the gas path adjusting device, and opens the fourth shut-off valve 25, and the fifth shut-off valve 22 is in a closed state, and inputs the high-pressure gas stored in the first pressure vessel 7 into the second pressure vessel 16 and the first safety valve test branch.

S24, performing a discharge pressure test on the first to-be-tested safety valve 26:

s241, the numerical control center 32 controls the gas path adjusting device to boost the pressure of the second pressure container 16, so that the gas pressure in the second pressure container 16 reaches 90% of the factory setting pressure, and then the gas path adjusting device is closed.

S242, the NC 32 controls the gas path adjusting device to continuously boost the pressure of the second pressure container 16, at the moment, the boosting speed is smaller than that of the step S241, and the boosting mode of increasing the gas pressure in the second pressure container 16 by 1% at intervals can be adopted, in the process, the NC 32 judges the pressure drop in the second pressure container 16 in real time according to the acquired data of the second pressure sensor 18 on the second pressure container 16, if the pressure drop rate exceeds a set threshold value, the first pressure drop is suddenly generated, and the gas pressure in the second pressure container 16 when the first pressure drop rate exceeds the set threshold value at the moment is recorded and is used as the actual setting pressure of the first safety valve 26 to be tested; otherwise, the pressurization is continued until the first pressure drop rate exceeds the set threshold, resulting in an actual set pressure for the first relief valve 26 to be tested.

S243, after the first pressure drop rate exceeds the set threshold, the numerical control center 32 controls the gas circuit adjusting device to continuously boost the second pressure container 16, and the boost speed is smaller than that of the step S241, and the boost speed can be used for boosting the gas pressure in the second pressure container 16 by 1% at intervals, in the process, the numerical control center 32 judges the pressure drop in the second pressure container 16 in real time according to the acquired data of the second pressure sensor 18, if the pressure drop rate exceeds the set threshold, the second pressure drop rapidly occurs, and the gas pressure in the second pressure container 16 when the second pressure drop rate exceeds the set threshold at the moment is recorded and is used as the actual discharge pressure of the first to-be-tested safety valve 26; otherwise, the pressurization is continued until the second pressure drop rate exceeds the set threshold value, resulting in the actual discharge pressure of the first relief valve 26 to be tested.

If the discharge pressure test of the first to-be-tested safety valve 26 is qualified, that is, the actual discharge pressure and the actual setting pressure of the first to-be-tested safety valve 26 both meet the calibration parameter range, the next test is performed, otherwise, the test is terminated and the test termination reason is reported.

S25, performing pressure maintaining test on the first to-be-tested safety valve 26:

S251, the numerical control center 32 controls the gas path adjusting device, so that after the gas pressure in the second pressure container 16 reaches 90% of the actual setting pressure, the gas path adjusting device is closed for testing the pressure maintaining performance of the first to-be-tested safety valve 26 under 90% of the actual setting pressure.

S252, the numerical control center 32 judges the pressure drop in the second pressure container 16 in real time according to the acquired data of the second pressure sensor 18 on the second pressure container 16, and if the pressure drop rate exceeds a set threshold or the pressure drop exceeds a set value in a set time, the first to-be-tested safety valve 26 does not maintain the pressure under 90% of factory setting pressure; otherwise, it means that the first relief valve 26 to be tested is held at an actual set pressure of 90%. In the invention, if the condition of non-pressure maintaining occurs, the reason of the non-pressure maintaining can be searched by combining the air tightness test.

And S253, after a period of time, the numerical control center 32 controls the gas circuit adjusting device to pressurize the second pressure container 16 once, so that the gas pressure in the second pressure container 16 is increased by 2% each time until the pressure is increased to the factory setting pressure, and the pressure maintaining performance of the first to-be-tested safety valve 26 under 92%, 94%, 96%, 98% and 100% of the actual setting pressure is respectively tested according to the mode of the step S252.

If the pressure maintaining test of the first to-be-tested safety valve 26 is qualified, that is, the pressure maintaining performance meets the range of the calibration parameters, the next test is performed, otherwise, the test is terminated and the reason for terminating the test is reported.

S26, carrying out a seat returning pressure test on the first to-be-tested safety valve 26:

s261, the numerical control center 32 controls the gas path adjusting device, and the gas path adjusting device is closed after the gas pressure in the second pressure container 16 reaches the set pressure; wherein the set pressure is the actual discharge pressure of the first relief valve 26 to be tested.

S262, the numerical control center 32 opens the discharging device, discharges the gas in the second pressure container 16 by using the discharging device, namely, reduces the pressure, and can reduce the pressure of the gas in the second pressure container 16 by adopting a mode of discharging 1% of the gas in the second pressure container 16 at intervals, the numerical control center 32 judges the pressure drop in the second pressure container 16 in real time according to the acquired data of the second pressure sensor 18 until the pressure of the gas in the second pressure container 16 is unchanged for the first time, namely, the pressure drop is 0, and records the pressure of the gas in the second pressure container 16 when the pressure drop is 0 at the moment, and the pressure is taken as the actual seat returning pressure of the first to-be-detected safety valve 26.

If the seat returning pressure test of the first to-be-tested safety valve 26 is qualified, that is, the actual seat returning pressure of the first to-be-tested safety valve 26 meets the calibration parameter range, the next test is performed, otherwise, the test is terminated and the test termination reason is reported.

S27, performing a pulse withstand voltage test on the first to-be-tested safety valve 26:

s271, the numerical control center 32 controls the gas path adjusting device to close the gas path adjusting device after the gas pressure in the second pressure container 16 reaches the set pressure; wherein the set pressure is the actual setting pressure of the first relief valve 26 to be tested.

S272, the nc center 32 opens the discharge means, and discharges the gas in the second pressure vessel 16 by using the discharge means until the gas pressure in the second pressure vessel 16 is discharged to zero.

S273, cycling the steps S271-S272, and after cycling for a plurality of times, judging whether the first safety valve 26 to be tested is damaged or not, wherein the judging mode is as follows:

according to the ways of steps S24 and S26, the discharge pressure test and the seat returning pressure test are performed on the first to-be-tested safety valve 26 again, so as to obtain the setting pressure, the discharge pressure and the seat returning pressure of the first to-be-tested safety valve 26 after the pulse pressure test at the moment, and judge whether the setting pressure, the discharge pressure and the seat returning pressure at the moment are in the range of the calibration parameters, if the setting pressure, the discharge pressure and the seat returning pressure are all in the range of the calibration parameters, the first to-be-tested safety valve 26 has the pulse pressure resistance; otherwise, the first relief valve 26 to be tested is not provided with impulse pressure resistance.

If the pulse withstand voltage test of the first safety valve 26 to be tested is qualified, the next test is performed, otherwise, the test is terminated and the reason for terminating the test is reported.

S28, performing a reliability test on the first safety valve 26 to be tested:

s281, the nc center 32 controls the temperature adjusting device to adjust the temperature of the gas in the second pressure vessel 16.

S282, according to the mode of the steps S24-S27, under different gas temperatures, a discharge pressure test, a pressure maintaining test, a seat returning pressure test and a pulse pressure withstand test are sequentially carried out on the first safety valve 26 to be tested, and the setting pressure, the discharge pressure, the pressure maintaining performance, the seat returning pressure and the pulse pressure withstand performance of the safety valve to be tested under different gas temperatures are tested.

If the reliability test of the first safety valve 26 to be tested is qualified, the next test is performed, otherwise, the test is terminated and the reason for the termination of the test is reported.

In this embodiment, the comprehensive test bench is used to perform a working environment test on the second safety valve 24 to be tested on the second safety valve test branch, and the specific manner is as follows:

s31, the second safety valve 24 to be tested is installed on a second safety valve test branch of the comprehensive test bench, and factory parameters of the second safety valve 24 to be tested are input into the numerical control center 32 as calibration parameters, comprising: nominal pressure, operating pressure, trim pressure, discharge pressure, seat back pressure, pressure rating, flow channel diameter, operating environment temperature range. In the initial state, all valves on the test bed are in a closed state, and all devices are in an unoperated state.

And S32, connecting the input end of the pressurizing device with an air source, inputting air to the pressurizing device, simultaneously, opening the air purifying device by the numerical control center 32, purifying the high-pressure air flowing out of the pressurizing device, entering the first pressure container 7, inputting the high-pressure air into the first pressure container 7, stopping inputting the air to the pressurizing device until the air pressure in the first pressure container 7 reaches the working pressure, and directly adopting the high-pressure air stored in the first pressure container 7 as a test air source in a subsequent test.

S33, the numerical control center 32 opens the gas path adjusting device, opens the fifth stop valve 22, and the fourth stop valve 25 is in a closed state, and inputs the high-pressure gas stored in the first pressure container 7 into the second pressure container 16 and the second safety valve test branch.

S34, the numerical control center 32 controls the environment adjusting bin 23 to adjust the working environment temperature of the second safety valve 24 to be tested, the temperature intervals are divided according to 5 ℃, and the temperature intervals of-40 ℃ to +65 ℃ are divided into 21 temperature intervals, so that 21 working environment temperatures are obtained.

And S35, respectively performing various tests on the second safety valve 24 to be tested at various working environment temperatures according to the mode of the steps S24-S28, wherein the tests comprise a discharge pressure test, a pressure maintaining test, a seat returning pressure test, a pulse pressure withstand test and a reliability test, and testing the working performance of the second safety valve 24 to be tested at different working environment temperatures.

In the invention, the numerical control center 32 also generates a test report of the safety valve to be tested according to the results of each test. Meanwhile, an operator can flexibly adjust test parameters, test items, test sequences and the like according to the types of the safety valves to be tested and the requirements of the use environment. For example, the discharge pressure test may be performed on the first to-be-tested safety valve 26 on the first safety valve test branch to obtain the actual setting pressure, then the air tightness test may be performed on the first to-be-tested safety valve 26, the air tightness test may be performed on the first to-be-tested safety valve 26 under 92%, 94%, 96%, 98%, 100% of the actual setting pressure by taking the actual setting pressure as a standard during the air tightness test, and then the pressure maintaining test, the seat returning pressure test, the pulse pressure withstanding test, and the reliability test may be performed on the first to-be-tested safety valve 26. The operator can also install a certain relief valve to be tested on the first relief valve test branch, and after the air tightness test, the pressure maintaining test, the back seat pressure test, the pulse withstand voltage test and the reliability test are carried out on the relief valve to be tested, each test is qualified, then the relief valve to be tested is installed on the second relief valve test branch, and then the working environment test is carried out on the relief valve to be tested, namely, the discharge pressure test, the pressure maintaining test, the back seat pressure test, the pulse withstand voltage test and the reliability test under each working environment temperature are carried out on the relief valve to be tested.

The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the present invention, and any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of the present invention.

Claims

1. A comprehensive test stand for a safety valve, the comprehensive test stand comprising: the pressure boosting device, the first pressure container (7), the temperature adjusting device, the gas path adjusting device, the second pressure container (16), the safety valve test branch and the safety valve to be tested are sequentially connected along the gas transmission direction;

the pressurizing device is used for pressurizing gas and inputting the pressurized gas into the first pressure container (7); the temperature regulating device is used for regulating the temperature of the gas flowing into the second pressure vessel (16); the gas path regulating device is used for regulating the flow rate of gas flowing into the second pressure container (16); the second pressure container (16) is used for storing gas with set pressure and set temperature and is used for testing the safety valve to be tested; the safety valve to be tested is connected with the second pressure container (16) through a safety valve test branch;

the second pressure vessel (16) is further connected to a discharge device for discharging the gas in the second pressure vessel (16);

The first pressure container (7) and the second pressure container (16) are respectively provided with a temperature sensor and a pressure sensor for collecting the gas temperature and the gas pressure in the pressure containers;

the comprehensive test bed also comprises an environment adjusting bin (23), wherein the safety valve to be tested is placed in the environment adjusting bin (23), and the environment adjusting bin (23) is used for providing different working environment temperatures for the safety valve to be tested;

the comprehensive test bed also comprises a numerical control center (32), wherein the numerical control center (32) is connected with each sensor and is used for receiving the acquired data of each sensor; the numerical control center (32) is also connected with each device and used for controlling each device;

the comprehensive test bed is used for carrying out the air tightness test on the safety valve to be tested, and the specific method is as follows:

s11, mounting a safety valve to be tested on a safety valve test branch of a comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center (32) as calibration parameters;

S12, connecting an input end of a pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device to input high-pressure air into a first pressure container (7) by a numerical control center (32);

s13, the numerical control center (32) opens the gas path regulating device, high-pressure gas stored in the first pressure container (7) is input into the second pressure container (16) and the safety valve test branch, and after the gas pressure in the second pressure container (16) is regulated to reach the set pressure by controlling the gas path regulating device, the gas path regulating device is closed; the set pressure is A% of the factory setting pressure of the safety valve to be tested;

s14, a numerical control center (32) opens a spraying device, sprays leakage measuring liquid to a safety valve to be measured, and closes the spraying device after the surface of the safety valve to be measured is soaked with the leakage measuring liquid;

s15, the numerical control center (32) opens an image acquisition device, acquires a surface image of the safety valve to be detected at the current moment, namely at the moment T1, and sends the surface image of the safety valve to be detected at the moment T1 to the numerical control center (32);

s16, after the interval delta T, acquiring a surface image of the safety valve to be detected at the current moment, namely at the moment T2, and sending the surface image of the safety valve to be detected at the moment T2 to a numerical control center (32); t2=t1+Δt;

S17, the numerical control center (32) performs contrast analysis on the surface images of the safety valve to be detected at the front moment and the rear moment according to the surface images of the safety valve to be detected at the front moment and the rear moment, namely the moment T1 and the moment T2:

s18, the numerical control center (32) controls the gas circuit adjusting device to boost the pressure of the second pressure container (16) until the gas pressure in the second pressure container (16) is increased by delta a% each time until the pressure reaches the factory setting pressure, and the safety valve to be tested is tested for air tightness under the factory setting pressure of (A+delta a)%, the factory setting pressure of (A+2 delta a)%, the factory setting pressure of (A+3 delta a)%, and the factory setting pressure according to the mode of the steps S14-S17;

S19, the numerical control center (32) controls a temperature adjusting device to adjust the gas temperature in the second pressure container (16), and the tightness of the safety valve to be tested is tested at different gas temperatures according to the mode of the steps S14-S18.

2. The comprehensive test bed for the safety valve according to claim 1, wherein the supercharging device comprises a high-pressure gas path and a normal-pressure gas path which are connected in parallel, the high-pressure gas path is provided with a first stop valve (1) and a booster pump (2), and the normal-pressure gas path is provided with a second stop valve (3); the discharging device comprises a second one-way valve (19), a third regulating valve (20) and a muffler (21) which are sequentially connected along the gas transmission direction.

3. The integrated test stand for safety valves according to claim 1, characterized in that the temperature regulating device comprises a cooler (10) and a heater (11).

4. The comprehensive test bed for the safety valve according to claim 1, wherein the gas path adjusting device comprises a third stop valve (12), a first one-way valve (13) and an adjusting valve assembly which are sequentially connected along a gas transmission direction; the regulating valve assembly comprises a first regulating valve (14) and a second regulating valve (15) which are connected in parallel; the first regulating valve (14) and the second regulating valve (15) are used for regulating the air quantity, and the regulating precision of the first regulating valve (14) is smaller than that of the second regulating valve (15).

5. The comprehensive test bench for a safety valve according to claim 1, wherein the spraying device comprises a liquid storage tank (28), a liquid pump (29), a third pressure sensor (30) and a spray header (31) which are sequentially connected along the liquid flow direction; the liquid storage tank (28) is used for storing leakage measuring liquid, the liquid pump (29) is used for adjusting hydraulic pressure, the third pressure sensor (30) is used for measuring hydraulic pressure, and the spray header (31) is located above the safety valve to be tested and used for spraying the safety valve to be tested.

6. The comprehensive test bed for the safety valve according to claim 1, wherein the camera (27) of the image acquisition device is arranged at the side of the safety valve to be tested, and performs rotary displacement along the surface of the safety valve to be tested, so as to acquire surface images of various angles of the safety valve to be tested.

7. The integrated test stand for a safety valve according to claim 1, characterized in that the integrated test stand further comprises gas cleaning means for cleaning the gas fed into the first pressure vessel (7); the purification treatment comprises dust removal, oil removal and water removal; the gas purification device comprises a dust remover (4), an oil remover (5) and a water remover (6) which are sequentially connected along the gas transmission direction.

8. The comprehensive test method suitable for the comprehensive test bed for the safety valve is characterized in that the comprehensive test bed is used for sequentially carrying out discharge pressure test, pressure maintaining test, seat returning pressure test, pulse pressure withstand test and reliability test on the safety valve to be tested, and the specific method is as follows:

s21, mounting a safety valve to be tested on a safety valve test branch of the comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center (32) as calibration parameters;

s22, connecting an input end of a pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device to input high-pressure air into a first pressure container (7) by a numerical control center (32);

s23, the numerical control center (32) opens the gas path adjusting device, and high-pressure gas stored in the first pressure container (7) is input into the second pressure container (16) and the safety valve test branch;

s24, performing a discharge pressure test on the safety valve to be tested:

s241, the numerical control center (32) controls the gas path regulating device to pressurize the second pressure container (16), and the gas path regulating device is closed after the gas pressure in the second pressure container (16) reaches the set pressure; the set pressure is A% of the factory setting pressure of the safety valve to be tested;

S242, the numerical control center (32) controls the gas path regulating device to continuously boost the pressure of the second pressure container (16), the boosting speed is smaller than that of the step S241, the numerical control center (32) judges the pressure drop in the second pressure container (16) in real time according to the collected data of the pressure sensor on the second pressure container (16), if the pressure drop rate exceeds a set threshold, the gas pressure in the second pressure container (16) when the first pressure drop rate exceeds the set threshold is recorded, and the gas pressure in the second pressure container (16) at the moment is used as the actual set pressure of the safety valve to be tested; otherwise, continuing to boost until the first pressure drop rate exceeds the set threshold value, and obtaining the actual setting pressure of the safety valve to be tested;

s243, after the first pressure drop rate exceeds the set threshold, the numerical control center (32) controls the gas circuit regulating device to continuously boost the pressure of the second pressure container (16), the boosting speed is smaller than that of the step S241, the numerical control center (32) judges the pressure drop in the second pressure container (16) in real time according to the acquired data of the pressure sensor on the second pressure container (16), if the pressure drop rate exceeds the set threshold, the gas pressure in the second pressure container (16) when the second pressure drop rate exceeds the set threshold is recorded, and the gas pressure in the second pressure container (16) at the moment is used as the actual discharge pressure of the safety valve to be tested; otherwise, continuing to boost until the second pressure drop rate exceeds the set threshold value, and obtaining the actual discharge pressure of the safety valve to be tested;

s25, carrying out pressure maintaining test on the safety valve to be tested:

s251, the numerical control center (32) controls the gas path regulating device to enable the gas pressure in the second pressure container (16) to reach the set pressure, and then the gas path regulating device is closed; the set pressure is A% of the actual setting pressure of the safety valve to be tested;

s252, the numerical control center (32) judges the pressure drop in the second pressure container (16) in real time according to the acquired data of the pressure sensor on the second pressure container (16), and if the pressure drop rate exceeds a set threshold or the pressure drop exceeds a set value in a set time, the to-be-detected safety valve does not maintain the pressure under the actual set pressure of A%; otherwise, the safety valve to be tested is kept under the factory setting pressure of A%;

s253, the numerical control center (32) controls the gas circuit adjusting device to boost the pressure of the second pressure container (16) until the gas pressure in the second pressure container (16) is increased by delta a% each time until the pressure is increased to the actual setting pressure, and the pressure maintaining performance of the safety valve to be tested under the actual setting pressure of (A+delta a)%, the actual setting pressure of (A+2 delta a)% and the actual setting pressure is tested according to the mode of the step S252;

s261, the numerical control center (32) controls the gas path adjusting device to enable the gas pressure in the second pressure container (16) to reach the set pressure, and then the gas path adjusting device is closed; the set pressure is the actual discharge pressure of the safety valve to be tested;

s262, the numerical control center (32) opens the discharge device, the discharge device is utilized to discharge the gas in the second pressure container (16), namely, the pressure drop in the second pressure container (16) is judged in real time by the numerical control center (32) according to the acquired data of the pressure sensor on the second pressure container (16) until the pressure of the gas in the second pressure container (16) is kept unchanged, namely, the pressure drop is 0, and the gas pressure in the second pressure container (16) when the pressure drop is 0 at the moment is recorded and is used as the actual seat returning pressure of the safety valve to be tested;

S27, performing pulse withstand voltage test on the safety valve to be tested:

s271, the numerical control center (32) controls the gas path regulating device to enable the gas pressure in the second pressure container (16) to reach the set pressure, and then the gas path regulating device is closed; the set pressure is the actual setting pressure of the safety valve to be tested;

s272, the numerical control center (32) opens a discharge device, and discharges the gas in the second pressure container (16) by using the discharge device until the gas pressure in the second pressure container (16) is discharged to zero;

s28, performing reliability test on the safety valve to be tested:

s281, the numerical control center (32) controls a temperature adjusting device to adjust the temperature of the gas in the second pressure container (16);

9. A comprehensive test method suitable for a comprehensive test stand for a safety valve according to claim 1, wherein the comprehensive test stand is used for carrying out a working environment test on the safety valve to be tested, and the specific method is as follows:

S31, mounting a safety valve to be tested on a safety valve test branch of the comprehensive test bed, and inputting factory parameters of the safety valve to be tested into a numerical control center (32) as calibration parameters;

s32, connecting the input end of the pressurizing device with an air source, inputting air into the pressurizing device, and controlling the pressurizing device to input high-pressure air into the first pressure container (7) by the numerical control center (32);

s33, the numerical control center (32) opens the gas path adjusting device, and high-pressure gas stored in the first pressure container (7) is input into the second pressure container (16) and the safety valve test branch;

s34, controlling an environment adjusting bin (23) by a numerical control center (32) to adjust the working environment temperature of the safety valve to be tested;

s35, respectively performing various tests on the safety valve to be tested at various working environment temperatures, and testing the working performance of the safety valve to be tested at different working environment temperatures.