A low-temperature safety valve test device

Abstract

The present invention relates to the technical field of liquid safety valve test equipment, specifically a cryogenic safety valve test device, comprising a pressure vessel, wherein the top of the pressure vessel is provided with two flange joints, a first cryogenic ball valve is installed on the upper part of one flange joint, and a vertical hollow tube is provided below. The upper end of the hollow tube passes through the flange joint and is connected to the first cryogenic ball valve, and a second cryogenic ball valve for exhaust and observation is installed on the upper part of the other flange joint. A dewar can pipe is installed at one end of the pressure vessel, and the outer end of the dewar can pipe is connected to a plurality of branch pipes, each branch pipe being equipped with a switch valve. In the cryogenic safety valve test device, by inserting the bottom end of the hollow tube into the interior of the pressure vessel to a depth of 3 / 4 of the vessel height, the vaporized low-temperature gas can be ejected from the bottom of the hollow tube. The pressure of the gas causes the liquid in the pressure vessel to enter from the bottom of the hollow tube and then eject from the upper end, rapidly cooling the safety valve under test and related components.

Description

Technical Field

[0001] The invention relates to the technical field of liquid safety valve test equipment, in particular to a low-temperature safety valve test device. Background Art

[0002] In numerous industrial fields, including petrochemicals, natural gas storage and transportation, and food freezing, cryogenic safety valves, as key equipment for ensuring the safe operation of cryogenic systems, play a vital role. They automatically open when system pressure exceeds a set point, releasing excess pressure and preventing serious accidents such as explosions and leaks caused by overpressure, thereby ensuring the stability and safety of the entire cryogenic system. Therefore, accurate and reliable performance testing of cryogenic safety valves is essential to ensuring their quality and safety.

[0003] Currently, existing cryogenic safety valve test equipment faces numerous practical challenges. For one thing, regarding temperature control, when the vapor pressure of the cryogenic medium within the test system is high (e.g., exceeding 2.0 MPa), the gas temperature rises significantly, making it difficult to meet the required temperature difference between the fluid at the valve inlet and the fluid within the test vessel (e.g., GB / T29026-2012, "Spring Direct-Loaded Safety Valve for Cryogenic Media," §6.3.4, which stipulates a temperature difference of no more than 30°C). This results in inaccurate test results and fails to truly reflect the performance of the cryogenic safety valve under actual operating conditions. Furthermore, from a cost perspective, according to F2.3 of TSG07-2019, "Technical Specifications for Safety of Special Equipment," cryogenic medium test equipment must meet operating pressures of no less than 6.4 MPa and a volume of no less than 0.5 m³. Filling such large-capacity pressure test tanks with liquid nitrogen for safety valve testing is expensive (at least over 3,000 yuan per tank). Without a transitional cryogenic ball valve, each tank can only test one safety valve, making the test cost extremely high and uneconomical. Furthermore, the structural design of existing test equipment is not rational, resulting in a cumbersome test process, long test times, and low efficiency, making it difficult to meet the needs of large-scale production testing. Summary of the Invention

[0004] The present invention aims to provide a cryogenic safety valve testing device to address the aforementioned problem, raised in the background art, that without a transitional cryogenic ball valve, a single tank of liquid nitrogen can only test the pressure of one safety valve, resulting in extremely high testing costs and poor economic efficiency. Furthermore, existing testing devices suffer from inadequate structural design, resulting in a cumbersome testing process, long testing times, and low efficiency, making them difficult to meet the needs of large-scale production testing.

[0005] To achieve the above-mentioned objectives, the present invention provides a cryogenic safety valve testing device, comprising a pressure vessel, wherein two flange joints are provided on the top of the pressure vessel, a first cryogenic ball valve is installed on the upper part of one flange joint, and a vertical hollow tube is provided below, the upper end of the hollow tube passes through the flange joint and is connected to the first cryogenic ball valve, and a second cryogenic ball valve for exhaust and observation is installed on the upper part of the other flange joint, one end of the pressure vessel is installed with a Dewar tank pipe, the outer end of the Dewar tank pipe is connected to a plurality of branch pipes for externally connecting to a Dewar tank containing liquid nitrogen, and each of the branch pipes is installed with a switch valve.

[0006] This setting sets up two flange joints on the top of the pressure vessel, which constitute the core connection hub. First, it is connected to the first cryogenic ball valve and the hollow tube. When the cryogenic safety valve is tested, the hollow tube guides the gas after the low-temperature medium in the pressure vessel is vaporized to the first cryogenic ball valve, and then transports it to the safety valve under test, thus realizing the construction of the pressure test environment; second, the second cryogenic ball valve is installed. During the liquid nitrogen filling stage, the liquid level can be observed through this valve. When the liquid nitrogen is close to full, the valve is closed. At the same time, it is used to discharge the remaining gas in the container after the test. The Dewar tank pipe and branch pipe are combined with the switch valve to realize the parallel connection of liquid nitrogen from multiple Dewar tanks, which can quickly fill the pressure vessel with liquid nitrogen, and the flow rate of liquid nitrogen in each branch pipe can be independently controlled by the switch valve.

[0007] As a preferred solution of the present invention, the bottom end of the hollow tube is inserted into the interior of the pressure vessel to a depth that is 3 / 4 of the height of the pressure vessel.

[0008] In this setting, the bottom end of the hollow tube is inserted into the pressure vessel to a depth of 3 / 4 of the vessel height. This depth design allows the low-temperature medium to fully accumulate at the bottom of the pressure vessel. When the low-temperature medium is vaporized, the gas flows upward from the bottom of the hollow tube, enabling sufficient heat exchange with the surrounding medium over a longer path, maintaining a low temperature, and ensuring that the temperature of the gas delivered to the safety valve being inspected is stable and in a low-temperature state.

[0009] As a preferred embodiment of the present invention, a vaporizer is provided at the lower part of the pressure vessel, one end of the vaporizer is connected to the bottom of the pressure vessel through a vaporization pipeline, and the other end of the vaporizer is connected to the interior of the upper end flange joint of the hollow tube through the vaporization pipeline.

[0010] This setup uses a vaporizer at the bottom of the pressure vessel connected to the bottom of the vessel and the upper flange joint of the hollow tube via vaporizer piping. When the vaporizer valve is opened, liquid nitrogen at the bottom of the pressure vessel flows into the vaporizer, where it is heated and vaporized. The vaporized gas then flows through the vaporizer piping into the hollow tube and is ejected from the bottom of the hollow tube, providing the low-temperature, high-pressure gas environment required for testing the safety valve under test while rapidly cooling the safety valve and related components.

[0011] As a preferred solution of the present invention, a vaporizer valve is installed on the vaporization pipeline.

[0012] This setting uses a vaporizer valve installed in the vaporization line to precisely regulate the flow of liquid nitrogen into the vaporizer, either manually or automatically, thereby controlling the rate and volume of liquid nitrogen vaporization. When a rapid pressure increase is required, the valve is opened wide to increase the flow of liquid nitrogen. When the pressure approaches the set pressure of the safety valve, the valve is closed to slow the pressure rise, achieving precise control of the pressure increase within the pressure vessel.

[0013] As a preferred solution of the present invention, a connecting disk is installed at the outer end of the first cryogenic ball valve, and a safety valve to be inspected is installed at the outer end of the connecting disk.

[0014] This feature uses a connecting plate at the outer end of the first cryogenic ball valve as a mounting platform for the safety valve under test. The safety valve under test is securely mounted on the connecting plate through bolts and other means. The connecting plate tightly interfaces with the first cryogenic ball valve, allowing low-temperature, high-pressure gas delivered from the hollow tube to pass smoothly through the first cryogenic ball valve and into the connecting plate, where it then acts on the safety valve under test, thereby testing its performance.

[0015] As a preferred solution of the present invention, a low-temperature stop valve and a low-temperature measuring point are installed on the side of the connecting plate.

[0016] This setting features a low-temperature shutoff valve mounted on the side of the connection plate, which can be used to cut off or open the gas flow path as needed during testing. For example, when testing the safety valve's reseat pressure, closing the low-temperature shutoff valve controls the rate of gas pressure drop, allowing for accurate observation of the valve's reseat condition. A platinum resistance temperature sensor is used at the low-temperature measurement point to monitor the gas temperature at the connection plate in real time and transmit the temperature data to a display or recording device, providing testers with temperature parameters.

[0017] As a preferred solution of the present invention, a safety valve is installed on the top of the pressure vessel, a pressure gauge is installed on the top of the pressure vessel, and a valve is installed on the pressure gauge.

[0018] This setting uses a safety valve mounted on top of the pressure vessel as a safety protection device. When the pressure inside the pressure vessel exceeds its set pressure due to an abnormal condition (such as a carburetor failure causing an uncontrolled pressure rise), the valve automatically opens to release pressure, preventing safety accidents such as explosions caused by overpressure. The pressure gauge is connected to the interior of the pressure vessel and displays the pressure value inside the vessel in real time. The tester can control the carburetor valve and other components based on the pressure gauge reading to adjust the pressure rise process.

[0019] As a preferred embodiment of the present invention, the outer wall of the pressure vessel is provided with an insulation layer, which is made of polyurethane foam material with a thickness of 50-80 mm. The outer surface of the insulation layer is wrapped with an aluminum foil reflective layer to reduce heat transfer and improve the insulation performance of the device.

[0020] The polyurethane foam insulation layer on the outer wall of the pressure vessel provides excellent thermal insulation, effectively preventing external heat from entering the vessel and reducing heat exchange between the cryogenic medium and the outside world. The aluminum foil reflective layer further enhances the insulation effect by reflecting external radiant heat, maintaining a stable low-temperature environment within the pressure vessel and reducing vaporization losses of the cryogenic medium.

[0021] As a preferred embodiment of the present invention, a support seat is provided at the bottom of the pressure vessel, and the support seat includes a base and a column. The column is fixed to the bottom of the pressure vessel by welding. Anchor bolt holes are provided on the base for fixing the support seat to the ground. Reinforcing ribs are provided between the column and the base to enhance the stability of the support seat.

[0022] The support base for the pressure vessel in this setup consists of a base, columns, and reinforcing ribs. The columns are welded to the bottom of the pressure vessel, providing vertical support. The base is fixed to the ground with anchor bolts to prevent displacement during the test. The reinforcing ribs strengthen the connection between the columns and the base, improving the overall stability of the support base and dissipating the pressure and vibration generated by the pressure vessel during the test.

[0023] As a preferred embodiment of the present invention, the outer end of the second cryogenic ball valve is connected to an exhaust pipe, and a muffler is provided at the outlet of the exhaust pipe to reduce the noise generated during exhaust. The exhaust pipe is made of stainless steel, and its inner diameter matches the diameter of the second cryogenic ball valve. The exhaust pipe and the second cryogenic ball valve are connected by a flange.

[0024] This test involves installing an exhaust pipe connected to the outer end of a second cryogenic ball valve. After the test is complete, the valve is opened to discharge the remaining low-temperature, high-pressure gas within the pressure vessel. The muffler at the exhaust pipe outlet, through a special acoustic structure design, absorbs, reflects, and interferes with the noise generated by the exhaust gas, reducing the exhaust noise intensity to meet environmental noise standards.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. In this cryogenic safety valve test device, by inserting the bottom end of a hollow tube into the interior of a pressure vessel to a depth of three-quarters of the vessel's height, and by combining a vaporizer with a vaporization line connection design, the vaporized cryogenic gas can be ejected from the bottom of the hollow tube, forming a long heat exchange path within the pressure vessel, effectively reducing the gas temperature. Practical verification has shown that this design can stably control the temperature difference between the fluid at the valve inlet and the fluid in the test vessel to within 10°C. Compared to existing devices that struggle to meet the standard of a temperature difference of no more than 30°C, this invention significantly improves temperature control accuracy, ensuring that the testing process fully complies with the requirements of Section 6.3.4 of GB / T29026-2012, "Spring Direct-Loaded Safety Valve for Cryogenic Media." This provides a realistic and reliable low-temperature operating environment for cryogenic safety valve performance testing, significantly improving the accuracy and effectiveness of test results.

[0027] 2. In the cryogenic safety valve test device, multiple Dewar tanks are used to fill liquid nitrogen in parallel through Dewar tank pipes and branch pipes, replacing the traditional method of filling a single large-capacity pressure test tank with liquid nitrogen. At the same time, the hollow tube and the first cryogenic ball valve and other structural designs are used to achieve that one tank of liquid nitrogen can be used for safety valve pressure testing multiple times. Compared with the existing technology, the present invention saves about 50% of liquid nitrogen loss. Taking the large-capacity test device that meets the requirements of TSG07-2019 "Technical Specifications for Safety of Special Equipment" as an example, the cost of each test is greatly reduced. In addition, the optimization of the device structure reduces unnecessary components and processes, further reduces equipment maintenance costs and labor costs, and significantly improves the economic performance of the test device, making it more cost-effective in large-scale production testing.

[0028] 3. In this cryogenic safety valve test device, the overall structural design of the device optimizes the test process from multiple aspects. Multiple Dewar tanks are filled with liquid nitrogen simultaneously, which greatly shortens the liquid nitrogen filling time; the rapid gasification and pressure increase design of the vaporizer and vaporization pipeline accelerates the process of the test device reaching the test pressure; the design of the hollow tube directly conveying cryogenic gas, while at the same time, the pressure of the gas causes the liquid in the pressure vessel to enter from the bottom of the hollow tube and then spray out from the top, quickly cooling the safety valve under test and related components, so that the safety valve under test can quickly cool and enter the test state; the liquid level observation and rapid exhaust function of the second cryogenic ball valve simplify the test preparation and termination process. These innovative designs work together to make the entire test process more compact and efficient, significantly improve test efficiency, better meet the needs of large-scale cryogenic safety valve testing in industrial production, and effectively improve the timeliness of production testing.

[0029] 4. This cryogenic safety valve test device features multiple safety enhancements. The safety valve installed on top of the pressure vessel serves as the device's final line of defense. When the pressure inside the vessel exceeds the set value due to an abnormal condition, it automatically opens to release pressure, preventing the pressure vessel from overpressurizing and exploding, thus ensuring the safety of the test device and personnel. The pressure gauge accurately displays the pressure inside the vessel in real time, providing intuitive data support for operators to adjust the pressure. This, combined with the vaporizer valve, enables precise pressure control and avoids safety hazards caused by sudden pressure changes. The polyurethane foam insulation layer and aluminum foil reflective layer on the outer wall of the pressure vessel effectively reduce heat transfer, maintain a stable low-temperature environment, and mitigate the risk of pressure fluctuations caused by the vaporization of the cryogenic medium. The bottom support base, with its stable structural design consisting of a base, columns, and reinforcement ribs, ensures that the device will not shake or tip over due to pressure fluctuations, vibration, or other factors during the test, providing a solid foundation for stable testing. Furthermore, the exhaust pipe and muffler connected to the outer end of the second cryogenic ball valve ensure a safe and environmentally friendly exhaust process after the test, not only discharging residual gas within the vessel but also reducing exhaust noise, meeting the safety and environmental requirements of industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0031] Figure 2 It is a structural schematic diagram of the Dewar tank connecting pipe in the present invention.

[0032] Figure 3 Schematic diagram of the structure of the hollow tube in the present invention.

[0033] The meaning of each number in the figure is:

[0034] 1. Pressure vessel; 11. Safety valve; 12. Pressure gauge; 2. Hollow tube; 21. Flange joint; 3. First cryogenic ball valve; 4. Second cryogenic ball valve; 5. Dewar tank connecting pipe; 51. Branch pipe; 52. On-off valve; 6. Vaporizer; 61. Vaporizer valve; 62. Vaporization pipeline; 7. Connecting plate; 71. Cryogenic stop valve; 72. Cryogenic measuring point; 73. Safety valve under inspection. DETAILED DESCRIPTION

[0035] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0036] The present invention provides a low temperature safety valve test device, such as Figure 1 、 Figure 2As shown, it includes a pressure vessel 1. Two flange joints 21 are provided on the top of the pressure vessel 1. A first cryogenic ball valve 3 is installed on the upper part of one flange joint 21, and a vertical hollow tube 2 is provided below. The upper end of the hollow tube 2 passes through the flange joint 21 and is connected to the first cryogenic ball valve 3. A second cryogenic ball valve 4 for exhaust and observation is installed on the upper part of the other flange joint 21. A Dewar tank pipe 5 is installed at one end of the pressure vessel 1. The outer end of the Dewar tank pipe 5 is connected to a plurality of branch pipes 51 for externally connecting to a Dewar tank containing liquid nitrogen. A switch valve 52 is installed on each branch pipe 51.

[0037] The two flange joints 21 at the top of the pressure vessel 1 form the core connection hub. First, they connect to the first cryogenic ball valve 3 and hollow tube 2. During a cryogenic safety valve test, the hollow tube 2 directs the vaporized gas from the cryogenic medium within the pressure vessel 1 to the first cryogenic ball valve 3, and then to the safety valve 73 under test, establishing a pressure test environment. Second, they house the second cryogenic ball valve 4, which allows the liquid level to be monitored during the liquid nitrogen filling phase and closed when the tank is nearly full. They also serve to vent any remaining gas from the vessel after the test.

[0038] like Figure 3 As shown, the Dewar canister pipe 5 and branch pipe 51 cooperate with the switch valve 52 to achieve parallel access to multiple Dewar canisters of liquid nitrogen, enabling rapid injection of liquid nitrogen into the pressure vessel 1. The liquid nitrogen flow rate of each branch pipe 51 can be independently controlled by the switch valve 52. Through the coordinated design of the double flange joint 21, the first cryogenic ball valve 3, the hollow tube 2, the second cryogenic ball valve 4, and the Dewar canister pipe 5 components, a complete cryogenic medium input, test environment construction, and exhaust process are constructed. The simultaneous injection of liquid nitrogen into multiple Dewar canisters significantly shortens the injection time and improves test efficiency. The observation and exhaust functions of the second cryogenic ball valve 4 ensure the visualization of the liquid nitrogen injection process and safe exhaust after the test, while also laying the foundation for precise control of temperature and pressure.

[0039] In this embodiment, Figure 1 As shown, the bottom end of the hollow tube 2 is inserted into the interior of the pressure vessel 1 to a depth of 3 / 4 of the height of the pressure vessel 1 .

[0040] The bottom end of hollow tube 2 is inserted into pressure vessel 1 to a depth of 3 / 4 of its height. This depth allows the cryogenic medium to accumulate fully at the bottom of pressure vessel 1. Once the cryogenic medium vaporizes, the gas flows upward from the bottom of hollow tube 2, enabling sufficient heat exchange with the surrounding medium over a long path, maintaining a low temperature and ensuring that the gas delivered to the safety valve 73 under inspection remains stable and at a low temperature. Precisely controlling the insertion depth of hollow tube 2 ensures the temperature stability of the vaporized cryogenic gas during delivery, effectively reducing the temperature difference between the fluid at the valve inlet and the fluid in the test vessel to within 10°C, meeting the strict temperature requirements of relevant standards and significantly improving the accuracy and reliability of test results.

[0041] Specifically, such as Figure 1 As shown, a vaporizer 6 is provided at the lower part of the pressure vessel 1 , one end of the vaporizer 6 is connected to the bottom of the pressure vessel 1 through a vaporization pipeline 62 , and the other end of the vaporizer 6 is connected to the interior of the upper end flange joint 21 of the hollow tube 2 through the vaporization pipeline 62 .

[0042] The vaporizer 6 at the bottom of the pressure vessel 1 is connected to the bottom of the vessel and the flange joint 21 at the upper end of the hollow tube 2 through the vaporizer pipe 62. When the vaporizer valve 61 is opened, the liquid nitrogen at the bottom of the pressure vessel 1 flows into the vaporizer 6, is heated and vaporized in the vaporizer 6, and the vaporized gas enters the hollow tube 2 through the vaporizer pipe 62 and is ejected from the bottom of the hollow tube 2, providing the low-temperature and high-pressure gas environment required for the test of the safety valve 73 under test. At the same time, the liquid in the pressure vessel 1 enters from the bottom of the hollow tube 2 through pressure and is then ejected from the upper end, rapidly cooling the safety valve 73 under test and related components. The connection design between the vaporizer 6 and the pipeline realizes the rapid vaporization and efficient transportation of liquid nitrogen, accelerates the pressurization process of the test device, and shortens the test preparation time. At the same time, the low-temperature gas is ejected directly from the bottom of the hollow tube 2, effectively reducing the temperature of the safety valve 73 under test and the test system, ensuring that the test process is carried out in a low-temperature environment and meeting the working conditions requirements of the low-temperature safety valve performance test.

[0043] Further, such as Figure 1 As shown, a vaporizer valve 61 is installed on the vaporization line 62.

[0044] The vaporizer valve 61 installed on the vaporization line 62 can precisely adjust the flow of liquid nitrogen into the vaporizer 6 through manual or automatic control, thereby controlling the vaporization speed and amount of liquid nitrogen. When rapid pressure increase is required, the valve is opened to increase the liquid nitrogen flow; when the pressure approaches the set pressure of the safety valve, the valve is closed to slow down the pressure rise rate, thereby achieving precise control of the pressure rise process in the pressure vessel 1. By adjusting the vaporizer valve 61, the rising rate of the test pressure can be flexibly controlled to ensure that the pressure rises steadily to the set pressure of the safety valve, avoiding the impact of sudden pressure changes on the safety valve. At the same time, it is convenient to accurately test the opening and return pressure of the safety valve, thereby improving the accuracy and reliability of the test results.

[0045] Furthermore, a connecting disk 7 is installed at the outer end of the first cryogenic ball valve 3 , and a safety valve 73 to be inspected is installed at the outer end of the connecting disk 7 .

[0046] The connecting plate 7 at the outer end of the first cryogenic ball valve 3 serves as the mounting carrier for the safety valve 73 to be inspected. The safety valve 73 to be inspected is securely mounted on the connecting plate 7 by bolting or other means. The connecting plate 7 is tightly docked with the first cryogenic ball valve 3, so that the low-temperature, high-pressure gas delivered from the hollow tube 2 can smoothly pass through the first cryogenic ball valve 3 into the connecting plate 7, and then act on the safety valve 73 to be inspected, thereby testing its performance. The setting of the connecting plate 7 provides a stable and reliable mounting structure for the safety valve 73 to be inspected, ensuring that the safety valve maintains the correct mounting position and sealing state during the test, preventing gas leakage from affecting the test results, and facilitating the rapid installation and disassembly of the safety valve, thereby improving test efficiency.

[0047] Further, such as Figure 1 As shown, a low-temperature stop valve 71 and a low-temperature measuring point 72 are installed on the side of the connecting plate 7.

[0048] The low-temperature stop valve 71 installed on the side of the connecting plate 7 can cut off or conduct the gas flow path as needed during the test. For example, when testing the return pressure of the safety valve, the gas pressure drop rate can be controlled by closing the low-temperature stop valve 71, so as to accurately observe the return of the safety valve. The low-temperature measuring point 72 uses a platinum resistance temperature sensor to monitor the gas temperature at the connecting plate 7 in real time, and transmits the temperature data to the display or recording device to provide temperature parameters for the tester. The setting of the low-temperature stop valve 71 increases the flexibility and controllability of the test process, and helps to accurately test the various performance indicators of the safety valve. The real-time and accurate temperature monitoring of the low-temperature measuring point 72 provides data support for judging whether the test process meets the standards, ensuring that the temperature is always within the specified range during the test process, and ensuring the validity and accuracy of the test results.

[0049] Further, such as Figure 1As shown, a safety valve 11 is installed on the top of the pressure vessel 1, a pressure gauge 12 is installed on the top of the pressure vessel 1, and a valve is installed on the pressure gauge 12.

[0050] The safety valve 11 installed on the top of the pressure vessel 1 serves as a safety protection device for the device. When the pressure inside the pressure vessel 1 rises out of control and exceeds its set pressure due to abnormal conditions such as a malfunction of the vaporizer 6, the valve automatically opens to release the pressure, thereby preventing the pressure vessel 1 from exploding due to overpressure and other safety accidents. The pressure gauge 12 is connected to the interior of the pressure vessel 1 and displays the pressure value inside the vessel in real time. The tester can control the vaporizer valve 61 and other components according to the reading of the pressure gauge 12 to adjust the pressure rising process. The setting of the safety valve 11 and the pressure gauge 12 provides a double safety guarantee and pressure monitoring means for the test device. The safety valve 11 ensures the safety of the device under abnormal conditions and avoids major safety accidents; the pressure gauge 12 enables the tester to intuitively understand the pressure changes and adjust the test parameters in time to ensure that the test process is safe, stable and accurate.

[0051] Furthermore, the outer wall of the pressure vessel 1 is provided with an insulation layer, which is made of polyurethane foam material with a thickness of 50-80 mm. The outer surface of the insulation layer is wrapped with an aluminum foil reflective layer to reduce heat transfer and improve the insulation performance of the device.

[0052] The polyurethane foam insulation layer on the outer wall of the pressure vessel 1 has a thickness of 50-80 mm, and the outer surface is wrapped with an aluminum foil reflective layer. The polyurethane foam insulation layer has good thermal insulation properties and can effectively prevent external heat from entering the interior of the container, reducing the heat exchange between the low-temperature medium and the outside world. The aluminum foil reflective layer further enhances the thermal insulation effect by reflecting external radiant heat, maintains the stability of the low-temperature environment inside the pressure vessel 1, and reduces the vaporization loss of the low-temperature medium. The combined design of the thermal insulation layer and the aluminum foil reflective layer significantly improves the thermal insulation performance of the device, reduces the heat absorption and vaporization of low-temperature media such as liquid nitrogen, and reduces the test cost. At the same time, a stable low-temperature environment helps to ensure temperature consistency during the test, improve the reliability of the test results, and avoid interference with the safety valve performance test due to temperature fluctuations.

[0053] Furthermore, a support seat is provided at the bottom of the pressure vessel 1, and the support seat includes a base and a column. The column is fixed to the bottom of the pressure vessel 1 by welding. Anchor bolt holes are provided on the base for fixing the support seat to the ground. Reinforcing ribs are provided between the column and the base to enhance the stability of the support seat.

[0054] The support seat at the bottom of pressure vessel 1 consists of a base and a column. The column is fixed to the bottom of pressure vessel 1 by welding, providing vertical support for the vessel. The base is provided with anchor bolt holes, which are fixed to the ground by anchor bolts to ensure that the device will not move during the test. Reinforcing ribs are provided between the column and the base to enhance the connection strength between the column and the base, improve the overall stability of the support seat, and disperse the pressure and vibration generated by pressure vessel 1 during the test. The structural design of the support seat provides a stable installation foundation for the test device, effectively preventing the device from shaking or tipping over due to factors such as pressure changes and vibration during the test, thereby ensuring the safety and stability of the test process. At the same time, stable support helps reduce errors in test results caused by device instability and improve the accuracy of test data.

[0055] Furthermore, the outer end of the second cryogenic ball valve 4 is connected to an exhaust pipe, and a muffler is provided at the outlet of the exhaust pipe to reduce the noise generated during exhaust. The exhaust pipe is made of stainless steel, and its inner diameter matches the diameter of the second cryogenic ball valve 4. The exhaust pipe and the second cryogenic ball valve 4 are connected by a flange.

[0056] The exhaust pipe connected to the outer end of the second cryogenic ball valve 4 opens the second cryogenic ball valve 4 after the test is completed to discharge the remaining low-temperature and high-pressure gas in the pressure vessel 1. The silencer arranged at the outlet of the exhaust pipe absorbs, reflects and interferes with the noise generated by the exhaust gas through a special acoustic structure design, thereby reducing the exhaust noise intensity and making it meet the environmental noise standards. The exhaust pipe is made of stainless steel, and its inner diameter matches the diameter of the second cryogenic ball valve 4. The exhaust pipe and the second cryogenic ball valve 4 are connected by a flange. The setting of the exhaust pipe and the silencer realizes a safe and environmentally friendly exhaust process after the test. The exhaust pipe ensures the smooth discharge of the gas in the container to avoid the residual gas from causing safety hazards to subsequent operations or device maintenance; the silencer reduces the exhaust noise, improves the test environment, reduces the harm of noise to operators, and meets the requirements of industrial production for noise control.

[0057] Finally, it should be noted that the electronic components in the carburetor 6 and other parts involved in this embodiment are all universal standard parts or parts known to those skilled in the art. Their structures and principles are known to those skilled in the art through technical manuals or conventional experimental methods. In the idle space of this device, all the above-mentioned electrical components are connected by wires. The specific connection means should refer to the working sequence between the electrical components in the above-mentioned working principle to complete the electrical connection, which is a well-known technology in the art.

[0058] When the cryogenic safety valve test device of the present invention is used, the device connection and inspection work must be completed before the cryogenic safety valve test is carried out. The safety valve 73 to be tested is installed on the outer end of the first cryogenic ball valve 3 through the connecting plate 7, and is connected by bolts and matched with a metal spiral wound gasket to ensure the sealing and stability of the connection, so that the safety valve 73 to be tested can withstand the test pressure and prevent gas leakage. At the same time, multiple Dewar tanks filled with liquid nitrogen are connected to each branch pipe 51 of the Dewar tank pipe 5 respectively, and are connected by threaded connection and reinforced with polytetrafluoroethylene raw tape. The switch valve 52 on the branch pipe 51 is opened to prepare for liquid nitrogen delivery. In addition, the first cryogenic ball valve 3 and the second cryogenic ball valve 4 at the two flange joints 21 at the top of the pressure vessel 1 are checked to ensure that they are in the closed state; confirm that the pressure gauge 12 valve is open and its range is within the range of 1.5-2 times the design pressure of the pressure vessel 1; check that the opening pressure setting value of the safety valve 11 is 1.1 times the design pressure of the pressure vessel 1, so as to ensure the safety of the test and the accuracy of the data.

[0059] By opening the on-off valves 52 on the multiple branch pipes 51, multiple Dewar tanks simultaneously and rapidly fill the pressure vessel 1 with liquid nitrogen. During this process, the liquid nitrogen filling level is monitored through a second cryogenic ball valve 4, which has a transparent valve stem, mounted on top of the pressure vessel 1. When the tank is nearly full, the second cryogenic ball valve 4 is closed, halting level monitoring and venting. This parallel filling of multiple Dewar tanks significantly shortens the filling time and improves test efficiency. The observation function of the second cryogenic ball valve 4 allows visualization of the filling process, ensuring that the required liquid nitrogen filling volume is met.

[0060] Open the vaporizer valve 61 on the vaporization line 62, and the liquid nitrogen at the bottom of the pressure vessel 1 flows into the vaporizer 6 under pressure. In the vaporizer 6, the liquid nitrogen is rapidly vaporized by heat, and the vaporized low-temperature and high-pressure gas is connected to the upper flange joint 21 of the hollow tube 2 through the vaporization line 62 and ejected from the bottom of the hollow tube 2. Since the bottom end of the hollow tube 2 is inserted into the interior of the pressure vessel 1 to a depth of 3 / 4 of the height of the vessel, the ejected low-temperature gas has a long path in the pressure vessel 1 to exchange heat with the surrounding medium, maintaining a low temperature state, while rapidly increasing the pressure in the vessel. At the same time, the pressure causes the liquid in the pressure vessel 1 to enter from the bottom of the hollow tube 2 and then eject from the upper end, rapidly cooling the safety valve 73 under test and related components, providing the required low-temperature and high-pressure environment for the test of the safety valve 73 under test, and rapidly cooling the safety valve 73 under test and related components, ensuring that the test is carried out under low-temperature conditions.

[0061] Continuously observe the pressure gauge 12. When the pressure in the pressure vessel 1 rises to a value close to the set pressure of the safety valve 73 under test, the pressure rise rate is controlled by adjusting the vaporizer valve 61 to ensure a steady pressure rise. The pressure causes the liquid in the pressure vessel 1 to enter from the bottom of the hollow tube 2 and then spray out from the top, rapidly cooling the safety valve 73 under test and related components. When the pressure reaches and exceeds the set pressure of the safety valve, the safety valve 73 under test opens to release the excessive pressure, and the opening pressure value at this time is recorded. Subsequently, when the pressure drops, observe whether the safety valve can return to its seat normally, and record the return pressure value. During the test, the low-temperature shut-off valve 71 on the side of the connecting plate 7 can cut off or conduct the gas flow path as needed. For example, when testing the return pressure, the valve can be closed to control the pressure drop rate so that the return condition can be accurately observed. The low-temperature measuring point 72 uses a platinum resistance temperature sensor to monitor the gas temperature at the connecting plate 7 in real time to ensure that the temperature is always within the specified range during the test, providing data support for the validity of the test results.

[0062] After the test is complete, close vaporizer valve 61 to stop the vaporization of liquid nitrogen. Slowly open the second cryogenic ball valve 4 and discharge the remaining low-temperature, high-pressure gas in pressure vessel 1 through the exhaust pipe connected to its outer end. The muffler at the exhaust pipe outlet reduces exhaust noise to meet environmental noise standards. Close the on-off valve 52 on the Dewar branch pipe 51 and disconnect the Dewar tank. After the pressure in pressure vessel 1 drops to atmospheric pressure, remove the safety valve 73 under inspection and clean the device for the next test.

[0063] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A cryogenic safety valve test device, comprising a pressure vessel (1), characterized in that: Two flange joints (21) are provided on the top of the pressure vessel (1), a first cryogenic ball valve (3) is installed on the upper part of one flange joint (21), and a vertical hollow tube (2) is provided below. The upper end of the hollow tube (2) passes through the flange joint (21) and is connected to the first cryogenic ball valve (3). A second cryogenic ball valve (4) for exhaust and observation is installed on the upper part of the other flange joint (21). A Dewar tank pipe (5) is installed at one end of the pressure vessel (1), and the outer end of the Dewar tank pipe (5) is connected to a plurality of branch pipes (51) for externally connecting to a Dewar tank containing liquid nitrogen. Each branch pipe (51) is installed with a switch valve (52); A vaporizer (6) is provided at the lower portion of the pressure vessel (1), one end of the vaporizer (6) is connected to the bottom of the pressure vessel (1) via a vaporizer pipe (62), and the other end of the vaporizer (6) is connected to the interior of the upper end flange joint (21) of the hollow tube (2) via the vaporizer pipe (62); A connecting disk (7) is installed at the outer end of the first cryogenic ball valve (3), and a safety valve (73) to be inspected is installed at the outer end of the connecting disk (7).

2. The cryogenic safety valve test device according to claim 1, characterized in that: The bottom end of the hollow tube (2) is inserted into the interior of the pressure vessel (1) to a depth equal to 3 / 4 of the height of the pressure vessel (1).

3. The cryogenic safety valve testing device according to claim 1, characterized in that: A vaporizer valve (61) is installed on the vaporization pipeline (62).

4. The cryogenic safety valve testing device according to claim 1, characterized in that: A low-temperature stop valve (71) and a low-temperature measuring point (72) are installed on the side of the connecting plate (7).

5. The cryogenic safety valve testing device according to claim 1, characterized in that: A safety valve (11) is installed on the top of the pressure vessel (1), a pressure gauge (12) is installed on the top of the pressure vessel (1), and a valve is installed on the pressure gauge (12).

6. The cryogenic safety valve testing device according to claim 1, characterized in that: The outer wall of the pressure vessel (1) is provided with an insulation layer, which is made of polyurethane foam material and has a thickness of 50-80 mm. The outer surface of the insulation layer is wrapped with an aluminum foil reflective layer to reduce heat transfer and improve the insulation performance of the device.

7. The cryogenic safety valve testing device according to claim 1, characterized in that: A support base is provided at the bottom of the pressure vessel (1), and the support base comprises a base and a column. The column is fixed to the bottom of the pressure vessel (1) by welding. Anchor bolt holes are provided on the base for fixing the support base on the ground. Reinforcing ribs are provided between the column and the base to enhance the stability of the support base.

8. The cryogenic safety valve testing device according to claim 1, characterized in that: The outer end of the second cryogenic ball valve (4) is connected to an exhaust pipe, and a muffler is provided at the outlet of the exhaust pipe to reduce the noise generated during exhaust. The exhaust pipe is made of stainless steel, and its inner diameter matches the diameter of the second cryogenic ball valve (4). The exhaust pipe and the second cryogenic ball valve (4) are connected via a flange.

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