CN217901138U - Leakage rate detection device for bolted flange connection system under simulated multi-working conditions - Google Patents

Abstract

The utility model discloses a bolt flange connected system leakage rate detection device under simulation multiplex condition, the device include that medium feed system, medium sealing system, leakage rate detecting system, load apply system, heating temperature regulating system and data acquisition analytic system. The utility model discloses a vacuum heat insulation seal structure has formed the collection that has good sealing performance and has leaked the cavity. The load applying system adopts an electro-hydraulic servo actuator and a load applying arm to apply vibration and bending moment to the bolt flange connecting system. The utility model discloses can simulate multiple operating condition, adopt the mode of collecting the leakage medium to measure the leakage rate of bolt flange joint system under the condition such as receiving temperature fluctuation, medium pressure fluctuation, moment of flexure and mechanical vibration, it is higher than the pressure drop method measurement accuracy commonly used. The device is used for measuring the leakage rate of the bolted flange connection system, monitoring the stress condition of the bolts and evaluating the sealing performance, so that the service life of the bolted flange connection system can be predicted, and the safety of the bolted flange connection system is ensured.

Description

Leakage rate detection device for bolted flange connection system under simulated multi-working conditions

technical field

The utility model provides a leakage rate detection device for a bolted flange connection system under simulated multi-working conditions. Leakage rate detection under vibration can be used to evaluate the sealing performance of the bolted flange connection system and predict its life.

Background technique

Bolted flange connection is a commonly used connection method in equipment and pipelines. Because of its advantages of easy disassembly and installation, it is widely used in petrochemical, chemical, nuclear power, metallurgy, pharmaceutical and other industries. In production and construction, due to the influence of the external environment, the temperature and medium pressure fluctuate, so the flange may undergo changes such as deflection, warping, creep, crack expansion, etc., and the stress of each part of the flange changes complicatedly; When there is torque or vibration, the stress characteristics of each part of the flange will also change greatly, and deflection, warping, and cracks may aggravate leakage. The flange device will also produce phenomena such as bolt loosening, fatigue and stress relaxation, which will bring safety hazards to the normal operation of the equipment. According to statistics, the leakage of bolted flange connection system is one of the main reasons for major accidents in petrochemical and other enterprises. Therefore, it is an urgent problem to be solved in engineering practice to study the influence of temperature and medium pressure fluctuations, external bending moment and mechanical vibration on the tightness of bolted flange connection system.

From the domestic and foreign development situation, the research on the tightness of the bolted flange connection system under the external bending moment and vibration environment only stays in the mechanical analysis of the failure of the bolted flange under the static load, and through the analysis of the flange and the gasket. The mechanical processing technology and the change of material properties can improve the sealing performance of the flange. At present, the theoretical analysis of the failure leakage of the bolted flange connection system under external bending moment and vibration load is not yet mature. Although someone abroad has conducted experiments on the loosening of a single bolt under the action of vibration, there is no relevant patent for a detailed analysis of the failure of the bolted flange connection system under the action of vibration, so it cannot be given that the bolted flange connection system is subject to external bending. Time criteria for failure under torque and vibration.

At present, under the fluctuation of temperature and medium pressure, as well as the action of external bending moment and mechanical vibration, there is no corresponding standard for the measurement method of the leakage rate of the bolted flange connection system. In actual production, the bolted flange connection caused by external loads The timing of system leaks and the magnitude of the leak rate are not known. In view of the above practical problems, the existing detection device is improved.

Contents of the invention

The utility model provides a leakage rate detection device of a bolted flange connection system under simulated multi-working conditions. The device can simulate the working conditions of the bolted flange connection system under the influence of temperature, medium pressure fluctuations, external bending moment and mechanical vibration. , and measure the leak rate.

The concrete technical scheme of the utility model is as follows:

A leakage rate detection device for a bolted flange connection system under simulated multi-working conditions includes a medium supply system, a medium sealing system, a leakage rate detection system, a load application system, a heating and temperature adjustment system, and a data acquisition and analysis system.

The medium sealing system includes a bolted flange connection system, a sealed outer cover body and a sealed inner cover body, the sealed outer cover body is covered outside the sealed inner cover body, and a sealed test chamber is formed between the two covers; the sealed outer cover body is provided with an upper pipeline and a sealed inner cover body. The lower pipe is connected by a bolted flange connection system, and a test gasket is provided at the flange fit.

The leak rate detection system includes a leak collecting cover, a leak collecting sealing assembly, a gas leak detecting pipeline and a leak detecting device. The leak collecting cover is covered outside the bolted flange connection system, and the upper end of the leak collecting cover is connected to the On the upper pipeline of the sealed outer cover body, the lower end of the leakage cover is sealed and connected with the leakage cover platform through the leakage cover bolt, and the leakage cover platform is welded to the outside of the lower pipeline of the sealed outer cover body.

The load application system is used to apply mechanical vibration and external bending moment to the bolted flange connection system, including an electro-hydraulic servo actuator and two load loading arms, and the two load loading arms are respectively connected to the upper pipe and the lower pipe of the sealed outer cover. The pipeline is connected, and the bottom of the pipeline lower head of the lower pipeline is also provided with universal wheels for rolling support.

Further, the leak collecting seal assembly of the leakage rate detection system includes a vacuum heat insulation sleeve, a heat insulation sleeve, an O-ring and an O-ring compression sleeve, and the vacuum heat insulation sleeve is welded outside the upper pipe of the sealed outer cover. , the vacuum heat insulation sleeve is equipped with a vacuum heat insulation cavity, and a heat insulation sleeve is set outside of it. The matching surfaces of the heat insulation sleeve and the O-ring compression sleeve are respectively provided with O-ring compression grooves, and the O-ring is pressed The tight groove is installed between the heat insulating sleeve and the O-ring compression sleeve, and the outer side of the O-ring compression sleeve is welded as a whole with the drain cover.

Further, the medium supply system is used to deliver the gaseous medium to the medium sealing system and realize the rise and fall of the medium pressure; it includes a gas cylinder, a pressure reducing valve, a surge tank, an intelligent electric control valve and an air intake pipeline connected in sequence; The intake duct is welded to the lower duct, between the load loading arm and the fixed bracket.

Further, the heating and temperature adjustment system includes a temperature controller and a resistance wire heater arranged in the sealed inner cover, and the resistance wire heater is inserted into the sealed inner cover from top to bottom, and installed on the upper pipe Top: The heating and temperature regulating system heats the gas medium through a resistance wire heater, and adjusts the temperature of the gas medium in the medium sealing system through a temperature controller, so as to simulate the fluctuation of the medium temperature of the bolted flange connection system under real working conditions.

Further, the data acquisition and analysis system includes a first temperature sensor arranged outside the test gasket, a second temperature sensor arranged at the inlet of the heat exchanger, a third temperature sensor arranged at the outlet of the heat exchanger and a device Strain gauges in bolted flange connection systems.

Further, there are eight strain gauges, which are respectively welded on the eight flange bolts of the bolt flange connection system, and are used to measure the bolt stress of each flange bolt when loaded.

A method for detecting the leakage rate of a bolted flange connection system under simulated multi-working conditions, based on the above-mentioned leakage rate detection device for a bolted flange connection system under simulated multi-working conditions, is used to simulate the temperature fluctuation, medium pressure fluctuation, and The external bending moment change and the operating state under multiple working conditions under different frequency mechanical vibrations and the measurement of the leakage rate include the following steps:

Step 1), measuring device installation:

1.1) Install the ball universal shaft at the bottom of the lower head of the lower pipe, and then install the universal wheel;

1.2) Install the test gasket on the lower flange of the bolted flange connection system;

1.3) Install the upper flange to the lower flange;

1.4) Install the strain gauge and the first temperature sensor, and the connecting wires of the strain gauge and the first temperature sensor are drawn out through the wiring hole A at the bottom of the leakage cover stand;

1.5) Install the leak collecting hood gasket on the leak collecting hood stand;

1.6) Install the leak collection cover, place the O-ring in the O-ring compression groove, press it through the heat insulation sleeve and the O-ring compression sleeve, and seal the cable at the bottom of the leak collection hood stand with sealant Seal the leakage of hole A to ensure good sealing of the leakage cover;

1.7) The fixed bracket includes the upper and lower fixed brackets. Fix the left side of the upper fixed bracket and the lower fixed bracket to the steel frame, and then move the above-mentioned installed device into the buckle of the fixed bracket, and fix the buckle to ensure that the device is in good condition. stability, and prepare for the subsequent application of bending moment and mechanical vibration;

1.8) Install the electro-hydraulic servo actuator on the steel frame;

1.9) Fix the buckle of the load loading arm on the upper pipe and the lower pipe, and install the load loading arm on the electro-hydraulic servo actuator;

1.10) Insert the resistance wire heater into the sealed inner cover from top to bottom, and install it on the top of the upper pipe, and its wires are drawn out from above;

1.11) Connect the connecting wires of strain gauges and temperature sensors with the data collector, connect the liquid crystal control panel with the electro-hydraulic servo actuator; connect the wires of the resistance wire heater with the temperature controller;

1.12) Connect the medium supply system with the intake pipe;

1.13) Connect the leak rate detection system with the gas leak detection pipeline;

Step 2), gas medium supply:

2.1) Open the valve of the gas cylinder to allow the gas medium to flow into the pipeline;

2.2) Open the pressure reducing valve, reduce the pressure of the gas medium, make the gas medium flow into the surge tank, and stabilize the pressure of the gas medium;

Step 3), test working condition adjustment:

3.1) Open the electro-hydraulic servo actuator and the liquid crystal control panel, and the electro-hydraulic servo actuator applies an external force of predetermined magnitude and vibration of predetermined frequency and amplitude to the bolted flange connection system through the load loading arm;

3.2) Calibrate the volume of the sealed leak-collecting chamber to obtain the volume V ₁ of the sealed leak-collecting chamber, the volume V ₂ of the pipe between the gas leakage detection pipe and the inlet side of the heat exchanger, and the pipe between the outlet side of the heat exchanger and the three-way valve volume V ₃ ;

3.3) Turn on the data acquisition and analysis system to ensure the normal operation of each sensor;

3.4) The resistance wire heater is powered on, and the sealed test chamber is heated through the adjustment of the resistance wire heater by the temperature controller;

3.5) Adjust the medium supply system, by adjusting the intelligent electric control valve, make the pressure in the medium sealing system reach the preset pressure, and realize the fluctuation of the pressure in the medium sealing system;

Step 4), leakage medium measurement:

4.1) Collect and analyze the temperature data of each temperature sensor in the analysis system, and the bolt load data measured by the strain gauges on each flange bolt;

4.2) According to the leakage rate, select one of the three leak detection methods of helium mass spectrometry leak detection method, U-shaped tube leak detection method and leak collection cavity pressurization method for measurement;

Step 5), end the experiment:

5.1) After the test, first close the medium supply system, and then exhaust the high-pressure gas in the sealing system;

5.2) Turn off the power and let the device cool down;

5.3) Remove the heating and temperature adjustment system, load application system and medium sealing system in order to replace the test gasket for the next test.

Further, the helium mass spectrometry leak detection method comprises the following steps:

1) Open the exhaust passage of the three-way valve, so that the leaked gas medium is discharged from the exhaust passage of the three-way valve to the outside;

2) Open the second exhaust valve, close the first exhaust valve and the third exhaust valve;

3) Open the three-way valve to connect the front and rear gas leak detection pipelines, and the gas medium is sucked into the helium mass spectrometer leak detector by the suction nozzle of the helium mass spectrometer leak detector through the gas leak detection pipeline;

4) Observe the reading change of the leak rate of the helium mass spectrometer leak detector, and record the leak rate.

Further, the leak-collecting cavity pressurization method includes the following steps:

1) Open the exhaust passage of the three-way valve, so that the leaked gas medium is discharged from the exhaust passage of the three-way valve to the outside;

2) Open the third exhaust valve, close the first exhaust valve and the second exhaust valve;

3) Open the three-way valve to connect the front and rear gas leakage detection pipelines, start timing, and use the micro-pressure sensor to measure the pressure of the medium at the outlet of the gas leakage detection pipeline;

4) The first temperature sensor measures the temperature T ₁ of the test pad;

5) The second temperature sensor measures the gas medium temperature _T2 at the inlet of the heat exchanger;

6) The third temperature sensor measures the gas medium temperature T ₃ at the outlet of the heat exchanger;

7) collect data through the data collector in the data collection and analysis system, and record the test data;

8) Substitute the volumes V ₁ , V ₂ and V ₃ and the temperatures T ₁ , T ₂ and T ₃ into the ideal gas state equation, first obtain the total moles of gas in the sealed leak-collecting cavity according to the ideal gas state equation, Then convert the number of moles of the leaked medium into the volume under the standard state, so as to measure the gas volume leakage rate per unit time.

Further, the U-shaped pipe leak detection method includes the following steps:

1) Open the exhaust passage of the three-way valve, so that the leaked gas medium is discharged from the exhaust passage of the three-way valve to the outside;

2) Open the first exhaust valve, close the second exhaust valve and the third exhaust valve;

3) Open the three-way valve to connect the front and rear gas leak detection pipes, start timing, and observe the height difference on both sides of the U-shaped pipe;

4) By observing the change of the liquid height difference on both sides of the U-shaped tube, the leakage rate is calculated.

Compared with the prior art, the utility model has the following beneficial effects:

1. The utility model can simulate a variety of actual working conditions, and measure the leakage rate of the bolted flange connection system under the conditions of temperature fluctuation, medium pressure fluctuation, bending moment and mechanical vibration by collecting leakage medium, so as to study different working conditions. The impact of environmental conditions on the leakage rate of the bolted flange connection system is more applicable than conventional measurement methods and is closer to the real situation.

2. The leakage rate detection device of the utility model is used to measure the leakage rate of the bolt flange connection system, monitor the stress of the bolt and evaluate the sealing performance, so that its life can be predicted and the bolt flange connection can be guaranteed. System security.

3. The utility model adopts a vacuum heat-insulating sealing structure to form a leak-collecting cavity with good sealing performance. The leak rate detection system adopts the leak-collecting sealing assembly, so that the leak-collecting cover and the sealed outer cover can be effectively sealed and matched. The leak-collecting seal assembly adopts vacuum heat insulation sleeve, heat insulation sleeve, O-ring and O-ring compression sleeve in turn. The vacuum heat insulation sleeve is insulated, and the heat insulation sleeve is further insulated. Both the heat insulation sleeve and the O-ring compression sleeve are provided with an O-ring compression groove, and the O-ring is arranged in the compression groove to enhance the sealing effect. The vacuum heat insulation sleeve is welded on the upper pipe, and the interior is a vacuum environment, which plays a role of heat insulation. The heat insulation sleeve wrapped in the outer layer is composed of heat insulation materials, the purpose is to prevent metal heat transfer, further play a role of heat insulation, and prevent The high temperature condition affects the sealing performance of the O-ring and improves the measurement accuracy.

4. The design of the load application system of the present invention can apply vibration and bending moment to the bolted flange connection system separately, and can also apply vibration and bending moment at the same time. Compared with the existing device only under the action of bending moment, the measurement accuracy of the leakage rate measured by the pressure drop method is higher. The pressure drop method has low measurement accuracy due to the influence of leakage at other locations. The utility model designs a leak-collecting sealing assembly for sealing, adopts the way of collecting the leakage medium to measure the rate, and has high measurement accuracy.

5. The leak-collecting cover in the device of the utility model not only plays the role of collecting the leakage medium, but also prevents damage to instruments and personnel due to the explosion caused by the blown out of the test gasket, which has high safety.

Description of drawings:

Below in conjunction with accompanying drawing and example the utility model is further described:

Fig. 1 is the utility model device structure schematic diagram;

Figure 2 is an enlarged view of B in Figure 1;

Fig. 3 is the structural representation of leak detection device in the utility model;

In the figure: 1. Upper pipe, 2. Vacuum heat insulation sleeve, 3. Heat insulation sleeve, 4. O-ring compression sleeve, 5. Upper flange, 6. Lower flange, 7. Flange bolts, 8. Set Leakage cover bolts, 9. Leakage cover gasket, 10. Leakage cover stand, 11. Gas leak detection pipeline, 12. Leak detection device, 13. Gas cylinder, 14. Pressure reducing valve, 15. Regulator tank, 16. Intelligent electric control valve, 17. Intake pipe, 18. Pipe lower head, 19. Ball universal shaft, 20. Universal wheel, 21. Resistance wire heater, 22. Lower pipe, 23. Test gasket , 24. The first temperature sensor, 25. Strain gauge, 26. Data collector, 27. Lower fixed bracket, 28. Computer, 29. Steel frame, 30. Electro-hydraulic servo actuator, 31. LCD control panel, 32 .Leak collection cover, 33.O-type sealing ring, 34. Load loading arm, 35. Sealed inner cover body, 36. Upper fixing bracket, 37. Temperature controller, 38. Second temperature sensor, 39. Heat exchanger, 40. The third temperature sensor, 41. Three-way valve, 42. The first exhaust valve, 43. U-shaped pipe, 44. Micro pressure sensor, 45. The second exhaust valve, 46. Helium mass spectrometer leak detector, 47 .Third exhaust valve.

Detailed ways:

Below in conjunction with accompanying drawing, the utility model is further described:

Embodiment one:

In Fig. 1, the leakage rate detection device of the bolted flange connection system under simulated multi-working conditions of the utility model includes six systems, namely: medium supply system, medium sealing system, leakage rate detection system, load application system, heating adjustment system Temperature system and data acquisition and analysis system.

Among them, the medium supply system is used to deliver the gas medium to the medium sealing system. The intelligent electric control valve 16 in the system can adjust the delivery pressure of the gas medium in a short time, realize the pressure rise and fall, and simulate the medium pressure fluctuation;

The medium sealing system is used to seal the test medium; it includes a bolted flange connection system, a sealed outer cover body and a sealed inner cover body 35, the sealed outer cover body is covered outside the sealed inner cover body 35, and a sealed test chamber is formed between the two covers; The outer cover body is provided with an upper pipe 1 and a lower pipe 22, which are connected by a bolted flange connection system, and a test gasket 23 is provided at the flange joint;

Leak rate detection system, used to measure the leakage rate of the medium leaked from the sealed test chamber; comprising a leak collecting cover 32, a leak collecting sealing assembly, a gas leak detecting pipeline 11 and a leak detecting device 12, and the leak collecting cover 32 is covered on Bolt flanges connect the outside of the system, the upper end of the leak collection cover 32 is connected to the upper pipe 1 of the sealed outer cover through the leak collection seal assembly, the lower end of the leak collection cover 32 is sealed and connected with the leak collection cover stand 10 through the leak collection cover bolts 8, and the collection Leaky mask stand 10 is welded outside the lower pipe 22 of the sealed outer cover body;

As shown in Figure 2, the leak collection seal assembly of the leak rate detection system includes a vacuum heat insulation sleeve 2, a heat insulation sleeve 3, an O-ring 33 and an O-ring compression sleeve 4, and the vacuum heat insulation sleeve 2 is welded on the sealing Outside the upper pipe 1 of the outer cover body, a vacuum heat insulation chamber is set inside the vacuum heat insulation sleeve 2, and a heat insulation sleeve 3 is arranged on the outside of the vacuum heat insulation sleeve 3. The mating surfaces of the heat insulation sleeve 3 and the O-ring compression sleeve 4 are respectively provided with O-ring compression Groove, O-type sealing ring 33 is installed between the heat insulating sleeve 3 and the O-ring compression sleeve 4 through the O-ring compression groove, and the outer side of the O-ring compression sleeve 4 is welded as one with the leakage cover 32.

The load application system is used to apply mechanical vibration and external bending moment to the bolted flange connection system, including an electro-hydraulic servo actuator 30 and two load loading arms 34, the electro-hydraulic servo actuator 30 is fixedly supported by a steel frame 29, The sealed outer cover body of the medium sealing system is also installed on the steel frame 29 through the fixed bracket. The two load loading arms 34 are respectively connected with the upper pipe 1 and the lower pipe 22 of the sealed outer cover, and the bottom of the lower pipe head 18 of the lower pipe 22 is also provided with a universal wheel 20 for rolling support.

The heating and temperature adjustment system is used for the adjustment and control of the temperature of the medium sealing system, and simulates temperature fluctuations; it includes a temperature controller 37 and a resistance wire heater 21 arranged in the sealed inner cover 35, and the resistance wire heater 21 is arranged from top to bottom Insert the sealed inner cover 35, and place it on the top of the upper pipe 1 through the flange structure of the resistance wire heater 21; the heating and temperature adjustment system heats the gas medium through the resistance wire heater 21, and adjusts the medium through the temperature controller 37 The gas medium temperature of the sealing system is used to simulate the fluctuation of the medium temperature of the bolted flange connection system under real working conditions.

The data acquisition and analysis system is used to collect and process the detection data of each sensor, obtain the bolt stress of the bolt flange connection system, the temperature data of the sealing test chamber, and the temperature change and pressure change at the gas leak detection pipeline. Including the first temperature sensor 24 arranged on the outside of the test gasket 23, the second temperature sensor 38 arranged at the inlet of the heat exchanger 39, the third temperature sensor 40 arranged at the outlet of the heat exchanger 39, and the bolt method Strain gauges 25 of the blue connection system. The data collection and analysis system may also include a data collector 26 , a computer 28 and a liquid crystal control panel 31 connected to an electro-hydraulic servo actuator 30 . There are 8 strain gauges 25, which are respectively welded on 8 flange bolts 7 of the bolted flange connection system, and are used to measure the bolt stress of each flange bolt 7 when loaded; the data collector 26 is respectively connected with the temperature sensor, the strain gauge The sheet 25, the micro-pressure sensor 44 are connected with the computer 28, and are used to measure the temperature change and pressure change of the medium, and provide temperature data for the leakage rate calculation of the leakage cavity pressurization method.

Embodiment two:

The leakage rate detection device in this example includes a medium supply system, a medium sealing system, a leakage rate detection system, a load application system, a heating and temperature adjustment system, and a data acquisition and analysis system. The specific structure is shown in Figure 1.

The medium supply system is used to deliver the gaseous medium to the medium sealing system and realize the rise and fall of the medium pressure; it includes a gas cylinder 13 , a pressure reducing valve 14 , a surge tank 15 , an intelligent electric control valve 16 and an air intake pipe 17 connected in sequence. The intake pipe 17 is welded on the lower pipe 22 and is located between the load loading arm 34 and the fixing bracket. The gas medium of the test can be helium, and the test is safe and convenient. The gas medium passes through the pressure reducing valve 14 from the gas cylinder 13 to the surge tank 15, and then passes through the intelligent electric control valve 16. The intelligent electric control valve 16 adopts a ball valve, which can adjust the delivery pressure of the medium gas in a short time to realize the rise and fall of the medium pressure , to simulate the fluctuation of the pressure of the gas medium in the actual working condition of the bolted flange connection system, and finally enter the intake pipe 17, and the gas medium enters the medium sealing system.

The medium sealing system includes a bolted flange connection system, a sealed inner cover body 35 and a sealed outer cover body. The bolted flange connection system includes an upper flange 5, a test gasket 23, a lower flange 6, and flange bolts 7; the upper flange 5 of the bolted flange connection system is welded to the upper pipe 1, and the lower flange 6 is welded to the lower pipe 22 , The lower end of the lower pipe 22 is welded together with the lower head 18 of the pipe, thereby forming a sealed outer cover; the cavity between the inner and outer covers forms a sealed test chamber. In this example, for better heat conduction, the sealed inner cover 35 is made of metal material.

Leakage rate detection system, including vacuum heat insulation sleeve 2, heat insulation sleeve 3, O-ring seal 33, O-ring compression sleeve 4, leak collection cover 32, leak collection cover stand 10, leak collection cover gasket 9, collection Leak cover bolts 8 , gas leak detection pipeline 11 and leak detection device 12 . The cross-section of the leak collecting hood stand 10 is circular, and is installed at the lower part of the welded part of the lower flange 6 and the lower pipe 22 . The leakage cover 32 is arranged outside the bolted flange connection system, and the leakage cover 32 is fixedly installed by the leakage cover bolts 8 , the leakage cover gasket 9 and the leakage cover stand 10 . The upper end of the leak collecting cover 32 is welded with the O-ring compression sleeve 4, and the vacuum heat insulation sleeve 2 is welded at the upper part where the upper flange 5 and the upper pipe 1 are welded. The inside of the vacuum heat insulation sleeve 2 is a vacuum environment, which plays a certain role in heat insulation. A layer of heat insulation sleeve 3 is wrapped on the outside of the vacuum heat insulation sleeve 2. The heat insulation sleeve 3 is composed of heat insulation materials to prevent metal heat transfer and further play a role The role of heat insulation. The heat insulation sleeve 3 and the O-ring compression sleeve 4 are provided with an O-ring compression groove. The O-ring 33 is placed in the compression groove of the O-ring, and is compressed by the heat insulating sleeve 3 and the O-ring compression sleeve 4, so as to achieve a sealing effect. A leak-collecting cavity is formed between the leak-collecting cover 32, the vacuum heat-insulating sleeve 2, the heat-insulating cover 3, the O-ring 33, the O-ring compression sleeve 4, and the leak-collecting cover stand 10; the leak-collecting cover stand One side of the bottom of 10 is provided with a gas leak detection pipeline 11, the gas leak detection pipeline 11 transports the leaked medium gas to the leak detection device 12, and the leak detection device 12 sequentially includes a second temperature sensor 38, a heat exchanger 39, a third The temperature sensor 40 and the three-way valve 41 are then divided into three paths, one path is delivered to the U-shaped pipe 43 through the first exhaust valve 42; the other path is connected to the third exhaust valve 47 and the micro pressure sensor 44; the last path passes through the second Exhaust valve 45 and helium mass spectrometer leak detector 46. Therefore, according to the size of the leak rate, one of the three leak detection methods can be selected to measure the leak rate. A wiring hole A is provided on the other side of the bottom of the leakage hood stand 10 , and the wires of the strain gauge 25 and the first temperature sensor 24 pass through the wiring hole A and are connected to the data collector 26 . After the wiring is completed, use a sealant to seal the wiring hole A to ensure good sealing performance of the leak collecting cavity.

The load application system includes an electro-hydraulic servo actuator 30, a load loading arm 34, an upper fixed bracket 36, a lower fixed bracket 27, and a universal wheel 20. The electro-hydraulic servo actuator 30 is fixed on a steel frame 29, and it can pass through The liquid crystal control panel 31 adjusts the magnitude of the external force applied to the upper pipe 1 and the lower pipe 22 as well as the frequency and amplitude of vibration, and then applies vibration and bending moment to the bolted flange connection system through the load loading arm 34 . Between the upper fixing bracket 36 and the upper flange 5 , and between the lower fixing bracket 27 and the lower flange 6 , there is a load loading arm 34 respectively. Between both sides of the load loading arm 34 and the top of the upper and lower pipelines, there is a fixed bracket connected to the steel frame 29 respectively, so as to fix the device. The fixed bracket interacts with the loading arm 34 to apply the bending moment and vibrations of different frequencies and amplitudes required for the test. At the bottom of the device, there is a universal wheel 20 that can be turned for 360°, which can facilitate the movement of the device and also support the measuring device. The load application system is used to simulate the mechanical vibration and external bending moment of the bolted flange connection system under actual working conditions.

The heating and temperature regulating system includes a resistance wire heater 21 and a temperature controller 37 arranged in a sealed inner cover 35 . The resistance wire heater 21 is inserted into the sealed inner cover body 35 from top to bottom, and placed on the top of the upper pipe 1 through the flange structure of the resistance wire heater 21, and its wires are drawn from above to communicate with the temperature controller 37. connect. The heating and temperature adjustment system heats the gas medium through the resistance wire heater 21, and adjusts the temperature of the gas medium in the medium sealing system through the temperature controller 37 to simulate the fluctuation of the medium temperature of the bolted flange connection system under real working conditions.

Data acquisition and analysis system, including the first temperature sensor 24 arranged on the outside of the test gasket 23, the second temperature sensor 38 at the inlet of the heat exchanger 39, the third temperature sensor 40 at the outlet of the heat exchanger 39 and the flange bolts 7 The strain gauge 25 on the top is also provided with a data collector 26, a computer 28 and a liquid crystal control panel 31. The bolted flange connection system is equipped with eight sets of bolted flange structures, and there are 8 strain gauges 25, which are respectively welded on the flange bolts 7, and are used to measure the bolt stress of each flange bolt 7 when loaded, so as to ensure that the bolt force is loaded It is accurate, and the bolt stress change of the flange bolt 7 can also be measured when vibration and bending moment are applied. The liquid crystal control panel 31 is connected to the electro-hydraulic servo actuator 30 through wires, and is used for displaying information such as the magnitude of the external force acting on the upper pipe 1 and the lower pipe 22, as well as the frequency and amplitude of vibration. The data collector 26 is respectively connected with the first temperature sensor 24, the second temperature sensor 38, the third temperature sensor 40, the strain gauge 25, the micro pressure sensor 44 and the computer 28, for measuring the temperature change and the pressure change of the medium, and The temperature change and gas medium pressure data are provided for the leakage rate calculation of the leakage collecting cavity pressurization method. The system takes the computer 28 as the core. Various sensors convert various measured parameters into analog voltage signals, amplify or attenuate them through the amplifier, and convert them into digital quantities through the A/D converter, and connect with the computer 28 through the input interface. The test results can be output through peripheral devices in different forms such as data, tables, curves or fitting formulas.

Embodiment three:

The further design of this embodiment is: in this example, the leakage rate measurement device of the bolted flange connection system under the action of vibration and bending moment, the medium supply system simulates the medium pressure fluctuation of the bolted flange connection system under actual working conditions; the load application system simulates The different bending moments and mechanical vibrations of the bolted flange connection system under actual working conditions are shown; the heating and temperature adjustment system simulates the temperature fluctuations of the bolted flange connection system under actual working conditions. Through the measurement of the leakage rate of the bolted flange connection system under actual working conditions, it is beneficial to improve the accuracy of the sealing performance evaluation and service life prediction of the bolted flange connection system.

The measuring device of the utility model can further carry out single-factor or multi-factor (such as temperature fluctuation, medium pressure fluctuation, mechanical vibration of different frequency and amplitude, bending moment of different size) on the leakage rate of the bolted flange connection system. Measure the leakage rate of the bolted flange connection system under the conditions of temperature fluctuation, medium pressure fluctuation, bending moment and mechanical vibration, so as to study the influence of different working conditions on the leakage rate of the bolted flange connection system.

Embodiment four:

The utility model simulates a method for detecting the leakage rate of a bolted flange connection system under multiple working conditions, comprising the following steps:

Step 1), measuring device installation:

1.1) Install the ball universal shaft 19 at the bottom of the lower head 18 of the lower pipe, and then install the universal wheel 20;

1.2) Install the test gasket 23 on the lower flange 6 of the bolted flange connection system;

1.3) Install the upper flange 5 on the lower flange 6;

1.4) Install the strain gauge 25 and the first temperature sensor 24, and the connecting wires of the strain gauge 25 and the first temperature sensor 24 are drawn out through the wiring hole A at the bottom of the drain hood stand 10;

1.5) Install the leak collecting cover gasket 9 on the leak collecting cover stand 10;

1.6) Install the leak collecting cover 32, place the O-ring 33 in the O-ring compression groove, compress it through the heat insulation sleeve 3 and the O-ring compression sleeve 4, and seal the leak collecting cover stand with sealant 10. Seal the leakage of cable hole A at the bottom, so as to ensure the good sealing performance of the leakage cover 32;

1.7) The fixed bracket includes upper and lower fixed brackets, fix the upper fixed bracket 36 and the left side of the lower fixed bracket 27 with the steel frame 29, then move the above-mentioned installed device into the buckle of the fixed bracket, fix the buckle, and Ensure good stability of the device and prepare for the subsequent application of bending moment and mechanical vibration;

1.8) installing the electro-hydraulic servo actuator 30 on the steel frame 29;

1.9) Fix the buckle of the load loading arm 34 on the upper pipe 1 and the lower pipe 22, and install the load loading arm 34 on the electro-hydraulic servo actuator 30;

1.10) Insert the resistance wire heater 21 into the sealed inner cover 35 from top to bottom, place it on the top of the upper pipe 1 by virtue of the flange structure of the resistance wire heater 21, and its wires are drawn out from above;

1.11) The connecting wires of the strain gauges 25 and each temperature sensor are connected with the data collector 26, the liquid crystal control panel 31 is connected with the electro-hydraulic servo actuator 30; the wires of the resistance wire heater 21 are connected with the temperature controller 37 connected;

1.12) The medium supply system is connected with the intake pipe 17;

1.13) connecting the leak rate detection system with the gas leak detection pipeline 11;

Step 2), gas medium supply:

2.1) Open the valve of the gas cylinder 13 to allow the gas medium to flow into the pipeline;

2.2) Open the pressure reducing valve 14 to reduce the pressure of the gas medium, so that the gas medium flows into the surge tank 15, and stabilize the pressure of the gas medium;

Step 3), test working condition adjustment:

3.1) Open the electro-hydraulic servo actuator 30 and the liquid crystal control panel 31, and the electro-hydraulic servo actuator 30 applies an external force of predetermined magnitude and vibration of predetermined frequency and amplitude to the bolted flange connection system through the load loading arm 34;

3.2) Calibrate the volume of the sealed leak-collecting chamber to obtain the volume V ₁ of the sealed leak-collecting chamber, the volume V ₂ of the pipeline between the gas leakage detection pipeline 11 and the inlet side of the heat exchanger 39; the outlet side of the heat exchanger 39 to the three-way valve Between 41 pipeline volume V ₃ ;

3.3) Turn on the data acquisition and analysis system to ensure the normal operation of each sensor;

3.4) Connect the resistance wire heater 21 to the power supply, and heat the inside of the sealed test chamber through the adjustment of the resistance wire heater 21 by the temperature controller 37;

3.5) Adjusting the medium supply system, by adjusting the intelligent electric control valve 16, the pressure in the medium sealing system reaches a preset pressure, and realizes pressure fluctuations in the medium sealing system;

Step 4), leakage medium measurement:

4.1) collecting and analyzing the temperature data of each temperature sensor in the analysis system, and the bolt load data measured by the strain gauge 25 on each flange bolt 7;

4.2) Select the appropriate leak detection method according to the leakage rate, such as helium mass spectrometry leak detection method, U-tube leak detection method or leak collecting cavity pressurization method for measurement;

Step 5), end the experiment:

5.1) After the test, first close the medium supply system, and then exhaust the high-pressure gas in the sealing system;

5.2) Turn off the power and let the device cool down;

5.3) Remove the heating and temperature adjustment system, the load application system and the medium sealing system in order to replace the test gasket 23 for the next test.

The utility model is adopted to simulate the real working state of the bolted flange connection system under the fluctuation of temperature and medium pressure, external bending moment and vibration, and measure its leakage rate, which can guide the replacement cycle of gaskets in the industry.

Embodiment five:

The further optional design of this example is: in Fig. 3, the test procedure that adopts helium mass spectrometry leak detection method to measure is as follows:

1) Open the exhaust passage of the three-way valve 41, so that the leakage gas medium is discharged to the outside from the outlet of the three-way valve 41 exhaust passage;

2) Open the second exhaust valve 45, close the first exhaust valve 42 and the third exhaust valve 47;

3) Open the three-way valve 41 so that the front and rear gas leak detection pipelines 11 are connected, and the gas medium is sucked into the helium mass spectrometer leak detector 46 by the suction nozzle of the helium mass spectrometer leak detector 46 through the gas leak detection pipeline 11;

4) Observe the reading change of the leak rate of the helium mass spectrometer leak detector 46, and record the leak rate.

Embodiment six:

The further optional design of this example is: since the utility model needs to simulate high-temperature working conditions, and the accuracy of the pressure drop method will be affected under high-temperature working conditions, it is more convenient to use the leak-collecting cavity pressurization method to measure the leakage rate. accurate. In Figure 3, in this example, the test steps for measurement using the leak-collecting cavity pressurization method are as follows:

1) Open the exhaust passage of the three-way valve 41, so that the leakage gas medium is discharged to the outside from the outlet of the three-way valve 41 exhaust passage;

2) Open the third exhaust valve 47, close the first exhaust valve 42 and the second exhaust valve 45;

3) Open the three-way valve 41 so that the front and rear gas leakage detection pipelines 11 are connected, and start timing, and use the micro pressure sensor 44 to measure the pressure of the medium at the outlet of the gas leakage detection pipeline 11;

4) The first temperature sensor 24 measures the temperature T ₁ of the test pad 23;

5) The second temperature sensor 38 measures the gas medium temperature T ₂ at the inlet of the heat exchanger 39;

6) The third temperature sensor 40 measures the gas medium temperature T ₃ at the outlet of the heat exchanger 39;

7) collect data by the data collector 26 in the data collection and analysis system, and record the test data;

8) Substitute volumes V ₁ , V ₂ and V ₃ and temperatures T ₁ , T ₂ and T ₃ into the ideal gas state equation, first obtain the total number of moles of the sealed leak-collecting cavity according to the ideal gas state equation, and then The number of moles of the leaked medium is converted into the volume under the standard state, so as to measure the gas volume leakage rate per unit time.

Embodiment seven:

The further optional design of this example is: in Fig. 3, the test procedure that adopts U-shaped pipe leak detection method to measure is as follows:

1) Open the exhaust passage of the three-way valve 41, so that the leakage gas medium is discharged to the outside from the outlet of the three-way valve 41 exhaust passage;

2) Open the first exhaust valve 42, close the second exhaust valve 45 and the third exhaust valve 47;

3) Open the three-way valve 41 so that the front and rear gas leakage detection pipelines 11 are connected, and start timing, and observe the height difference between the two sides of the U-shaped pipe 43;

4) By observing the change of the liquid height difference on both sides of the U-shaped pipe 43, the leakage rate is calculated.

Claims (6)

1. The utility model provides a bolted flange connected system leakage rate detection device under simulation multiplex condition, includes that medium feed system, medium sealing system, leakage rate detecting system, load apply system, heating temperature regulating system and data acquisition analytic system, its characterized in that:

the medium sealing system comprises a bolt flange connecting system, a sealing outer cover body and a sealing inner cover body (35), wherein the sealing outer cover body covers the sealing inner cover body (35), and a sealing test cavity is formed between the two cover bodies; the sealed outer cover body is provided with an upper pipeline (1) and a lower pipeline (22) which are connected through a bolt flange connecting system, and a test gasket (23) is arranged at the flange matching position;

the leakage rate detection system comprises a leakage collecting cover (32), a leakage collecting sealing assembly, a gas leakage detecting pipeline (11) and a leakage detecting device (12), wherein the leakage collecting cover (32) covers the outside of the bolt flange connecting system, the upper end of the leakage collecting cover (32) is connected to an upper pipeline (1) of the sealed outer cover body through the leakage collecting sealing assembly, the lower end of the leakage collecting cover (32) is connected with a leakage collecting cover rack (10) in a sealing mode through a leakage collecting cover bolt (8), and the leakage collecting cover rack (10) is welded to the outside of a lower pipeline (22) of the sealed outer cover body;

the load applying system is used for applying mechanical vibration and bending moment to the bolt flange connecting system and comprises an electro-hydraulic servo actuator (30) and two load applying arms (34), the two load applying arms (34) are respectively connected with an upper pipeline (1) and a lower pipeline (22) of a sealed outer cover body, and universal wheels (20) supported in a rolling mode are further arranged at the bottom of a lower pipeline sealing head (18) of the lower pipeline (22).

2. The device for detecting the leakage rate of the bolted flange connection system under the simulated multi-working condition according to claim 1, is characterized in that: leak rate detecting system's collection is leaked seal assembly and is included vacuum insulation cover (2), adiabatic cover (3), O type sealing washer (33) and O type circle and is compressed tightly cover (4), the welding of vacuum insulation cover (2) is outside sealed dustcoat's last pipeline (1), establishes vacuum heat insulating chamber in vacuum insulation cover (2), and its outside sets up adiabatic cover (3), and adiabatic cover (3) compress tightly the fitting surface of cover (4) with O type circle and are equipped with O type circle respectively and compress tightly the groove, and O type sealing washer (33) compress tightly the groove through O type circle and install between adiabatic cover (3) and O type circle and compress tightly cover (4), and O type circle compresses tightly the cover (32) welding as an organic whole with the collection in the cover (4) outside.

3. The device for detecting the leakage rate of the bolted flange connection system under the simulated multi-working condition according to claim 1 or 2, characterized in that: the medium supply system is used for conveying gas media to the medium sealing system and comprises a gas cylinder (13), a pressure reducing valve (14), a pressure stabilizing tank (15), an intelligent electric control valve (16) and a gas inlet pipeline (17) which are communicated in sequence.

4. The device for detecting the leakage rate of the bolted flange connection system under the simulated multi-working condition according to claim 3, is characterized in that: the heating and temperature regulating system comprises a temperature controller (37) and a resistance wire heater (21) arranged in a sealed inner cover body (35), wherein the resistance wire heater (21) is inserted into the sealed inner cover body (35) from top to bottom and is arranged at the top end of the upper pipeline (1).

5. The device for detecting the leakage rate of the bolted flange connection system under the simulated multi-working condition according to claim 3, characterized in that: the data acquisition and analysis system comprises a first temperature sensor (24) arranged on the outer side of a test gasket (23), a second temperature sensor (38) arranged at an inlet of a heat exchanger (39), a third temperature sensor (40) arranged at an outlet of the heat exchanger (39), and a strain gauge (25) arranged on a bolt flange connection system.

6. The device for detecting the leakage rate of the bolted flange connection system under the simulated multi-working condition according to claim 5, characterized in that: the eight strain gauges (25) are respectively welded on eight flange bolts (7) of the bolt flange connection system and used for measuring bolt stress of each flange bolt (7) during loading.

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