Ultralow-temperature liquid intrusive pressure sensor calibration system and pressure sensor

Abstract

The utility model discloses an ultralow-temperature liquid intrusive pressure sensor calibration system which comprises a vacuum heat insulation cavity, a temperature control cavity assembly, a pressure control cavity assembly, a pressure control gas assembly, a standard differential pressure gauge and a test cavity assembly. The pressure control cavity assembly comprises a pressure control cavity, a pressure control cavity liquid inlet pipeline and a pressure control cavity exhaust pipeline; the pressure control cavity comprises an upper cavity body, a long neck tube and a lower cavity body; two ends of the long-neck tube are respectively communicated with the upper cavity and the lower cavity; the temperature control cavity assembly wraps the lower cavity, and an ultralow temperature test board in the test cavity assembly is connected with the lower cavity; a pressure control cavity liquid inlet pipeline, a pressure control cavity exhaust pipeline and a pressure control gas assembly penetrate through the vacuum heat insulation cavity and then are communicated with the upper cavity; and the standard differential pressure gauge is connected with the upper cavity. According to the utility model, not only can the influence of gas-liquid mixing relative output pressure be avoided, but also different pressure calibration tests of fixed-point temperature maintenance can be realized so as to meet the research and calibration requirements of an ultralow-temperature liquid intrusive pressure sensor.

Description

Technical Field

[0001] The utility model relates to the technical field of ultra-low temperature pressure sensor pressure calibration, in particular to an ultra-low temperature liquid intrusion pressure sensor calibration system and a pressure sensor. Background Art

[0002] As the primary instrument for measuring pressure, pressure sensors play a vital role in inspection or testing. When using a pressure-inducing tube to measure cryogenic liquid pressure, ambient temperature pressure sensors suffer from a significant drawback, such as response lag and an inability to obtain high-frequency pressure pulsation values.

[0003] With the development of aerospace, aviation, industrial transportation, and other fields, the use of cryogenic fuels such as liquid hydrogen and liquid oxygen is becoming increasingly widespread. These low-temperature environments place higher demands on pressure measurement. Cryogenic pressure sensors play a vital role in these fields, ensuring the safe and stable operation of the systems. This is especially true in spacecraft cryogenic propulsion and refueling systems, where the harsh test conditions and operating environment determine the importance of high-precision measurement of cryogenic pressure parameters.

[0004] Ultra-low temperature liquid intrusive pressure sensors can directly contact and measure the working fluid being measured, and can obtain accurate cryogenic propellant pipeline pressure parameters in real time, achieving high-precision measurement of cryogenic propellant pressure. They have become a key measurement component for improving the performance of propellant filling measurement and control systems, and are highly favored by researchers in the field of aerospace liquid hydrogen / liquid oxygen engine measurement and control.

[0005] Under low temperature conditions, the thermal expansion and contraction of the pressure-sensitive element material of the pressure sensor, the influence of the internal structure and the manufacturing process will cause the sensor to have zero drift and sensitivity temperature drift. For the pressure sensor, if the calibration temperature and the operating temperature are different, a certain additional error will be generated, affecting its working performance.

[0006] At present, there are roughly two types of calibration devices for low-temperature pressure sensors at home and abroad. One is a calibration device under room temperature conditions. However, since the measurement error of low-temperature pressure sensors can reach 10% due to the influence of temperature performance, it cannot more accurately display the actual effect of low-temperature pressure measurement. It is often used to calibrate industrial low-temperature pressure sensors with low error requirements.

[0007] The other is a device that performs calibration at low temperatures. However, the working principle of this calibration device is to cool the introduced gas through heat conduction to achieve a low-temperature environment, and to change the pressure of the introduced gas for pressure calibration. However, this calibration method cannot accurately simulate the actual test environment of the cryogenic liquid intrusive cryogenic sensor. In addition, the introduced gas almost always uses helium with a low boiling point, which is different from the actual measured liquid working fluid.

[0008] Currently, the development of ultra-low temperature liquid intrusive pressure sensors is still in its infancy. There are no public reports or detailed descriptions of the relevant ultra-low temperature liquid intrusive calibration platform. It basically focuses on using gas pressure to perform sensor calibration tests at low temperatures, rather than directly performing liquid intrusive testing and calibration. This has limitations, does not conform to the ultra-low temperature liquid intrusive working fluid measurement status, and cannot meet mission requirements.

[0009] When performing calibration measurements on the calibration device of the ultra-low temperature liquid intrusion pressure sensor, it is necessary to ensure that the sensitive diaphragm of the sensor is in full contact with the cryogenic liquid, fully consider the accuracy of pressurization, overcome factors such as the influence of the liquid temperature gradient on the measurement, and at the same time avoid the influence of the relative pressure output of the gas-liquid mixture as much as possible. Only in this way can the ultra-low temperature liquid intrusion pressure sensor be calibrated more accurately.

[0010] In the prior art, the utility model patent with the patent publication number CN115389099A discloses a pressure sensor calibration device, in which the insulation cylinder is formed with a first interlayer cavity, and the first interlayer cavity is filled with a liquid low-temperature medium. When the liquid low-temperature medium reaches the set liquid level, a low-temperature environment can be created in the cylinder cavity of the insulation cylinder, and the test core is surrounded by the low-temperature environment. The ambient temperature created by the insulation cylinder is more stable, and the pressure sensor can be calibrated in a low-temperature environment. However, this method forms the low-temperature temperature of the test by heat conduction, and there is no direct contact with the low-temperature liquid working medium of the test. The calibration test is performed using gas pressure, which does not meet the requirements of liquid invasive testing.

[0011] Patent publication number CN107941261A discloses a low-temperature test bench for sensor equipment, comprising a thermostat, an integrated tooling platform, and a preloading device. The thermostat is equipped with a liquid helium pool, and the integrated tooling platform is located within the liquid helium pool. The preloading device includes a vacuum tube, a transmission unit, and a force loading control unit. The transmission unit is located within the vacuum tube and is connected to the transmission unit. The force loading control unit is sealed to the vacuum tube, and the vacuum tube is sealed to the top opening of the thermostat via a flange. The outermost layer of the integrated tooling platform is a vacuum box, which is sealed to the vacuum tube of the preloading device. The vacuum box contains a test fixture for mounting the sensor equipment to be tested. The transmission unit in the vacuum tube is connected to the test fixture, which facilitates the measurement of the performance of low-temperature sensors under continuously changing temperatures. However, in this patent, the low-temperature pressure sensor is placed in a vacuum environment and tested as a mechanical pressure sensor, which is essentially different from a liquid-intrusive pressure sensor. Utility Model Content

[0012] The technical problem to be solved by the present invention is to solve the problem that the current calibration platform of ultra-low temperature liquid intrusive pressure sensor has limitations, does not conform to the ultra-low temperature liquid intrusive working medium measurement state, and cannot meet the task requirements.

[0013] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0014] A calibration system for an ultra-low temperature liquid intrusive pressure sensor includes a vacuum insulation chamber 10, a temperature control chamber assembly 20, a pressure control chamber assembly 30, a pressure control gas assembly 40, a standard differential pressure gauge 50, and a test chamber assembly 60;

[0015] The pressure control chamber assembly 30 includes a pressure control chamber 31, a pressure control chamber liquid inlet pipeline, and a pressure control chamber exhaust pipeline. The pressure control chamber 31 includes an upper chamber 311, a long neck tube 312, and a lower chamber 313. The two ends of the long neck tube 312 are respectively connected to the upper chamber 311 and the lower chamber 313.

[0016] The temperature control chamber assembly 20 wraps the lower chamber 313 , and the ultra-low temperature test bench 62 in the test chamber assembly 60 is connected to the lower chamber 313 ;

[0017] The pressure control chamber liquid inlet pipeline, the pressure control chamber exhaust pipeline, and the pressure control gas assembly 40 pass through the vacuum insulation chamber 10 and are connected to the upper chamber 311;

[0018] A standard differential pressure gauge 50 is connected to the upper cavity 311, and a pressure control cavity pressure sensor 321 is provided on the pressure control cavity liquid inlet pipeline. The standard differential pressure gauge 50 and the pressure control cavity pressure sensor 321 respectively test the gas pressure and liquid pressure of the gas space in the upper cavity 311, and the sum of the two is used as the calibration comparison pressure.

[0019] In one embodiment of the present invention, the temperature control chamber assembly 20 includes a temperature control chamber 21, and the temperature control chamber 21 is in an inverted concave shape, and a mounting opening is provided in the central concave portion; the lower cavity 313 partially protrudes from the mounting opening to form a test platform mounting opening.

[0020] In one embodiment of the present invention, the temperature control chamber assembly 20 includes a temperature control chamber liquid inlet pipeline and a temperature control chamber exhaust pipeline; the temperature chamber liquid inlet pipeline and the temperature control chamber exhaust pipeline are both connected to the temperature control chamber 21, and a temperature control chamber liquid inlet valve 22 is provided on the temperature chamber liquid inlet pipeline, and a temperature control chamber exhaust valve 23 is provided on the temperature control chamber exhaust pipeline.

[0021] In one embodiment of the present invention, a pressure control chamber liquid inlet valve 322 is further provided on the pressure control chamber liquid inlet pipeline; a gas proportional valve 331 and a flow controller 332 are sequentially provided on the pressure control chamber exhaust pipeline.

[0022] In one embodiment of the present invention, the test chamber assembly 60 includes a test chamber bellows tube 61 and a test chamber top flange 63;

[0023] A test installation port is provided at the bottom of the vacuum insulation chamber 10, and the ultra-low temperature test table 62 is fixed to the test platform installation port through a detachable sealing flange of the test installation port;

[0024] The test cavity bellows tube 61 is connected to the concave portion of the temperature control cavity 21 through the test installation port at one end; the test cavity top flange 63 is detachably connected to the other end of the test cavity bellows tube 61;

[0025] The inner recess of the temperature control cavity 21 , the test cavity bellows 61 , the ultra-low temperature test platform 62 and the test cavity top flange 63 enclose and form a test cavity 67 .

[0026] In one embodiment of the present invention, the test chamber assembly 60 includes a test chamber radiation screen hanging rod 64, a test chamber radiation screen 65, and a test chamber evacuation valve 66;

[0027] The test chamber radiation screen hanging rod 64 is fixedly connected to the test chamber top flange 63, and multiple test chamber radiation screens 65 are fixed on the test chamber top flange 63. The test chamber top flange 63 and the test chamber radiation screens 65 are located in the test chamber 67; and the pipeline where the test chamber evacuation valve 66 is located passes through the test chamber top flange 63 and is connected to the test chamber 67.

[0028] In one embodiment of the present invention, the pressure-controlled gas assembly 40 includes a pressure-controlled gas inlet pipe 41 , a pressure-stabilizing chamber 42 , and a high-pressure helium cylinder 43 ;

[0029] Both ends of the pressure-controlled air inlet pipe 41 are connected to the pressure-stabilizing chamber 42 and the upper cavity 311 respectively, and the outlet of the high-pressure helium cylinder 43 is connected to the pressure-stabilizing chamber 42 .

[0030] In one embodiment of the present utility model, the pressure-control gas assembly 40 includes a pressure reducing valve 44, a pressure stabilizing chamber safety valve 45 and a pressure stabilizing chamber pressure sensor 46; the pressure reducing valve 44 is located on the pipeline connecting the high-pressure helium cylinder 43 and the pressure stabilizing chamber 42, and the pressure reducing valve 44 and the pressure stabilizing chamber safety valve 45 are connected to the pressure stabilizing chamber 42.

[0031] In one embodiment of the present invention, the vacuum insulation chamber 10 includes a vacuum chamber outer tube 11 and a vacuum chamber flange cover 12 ; the vacuum chamber flange cover 12 and the vacuum chamber outer tube 11 are detachably sealed, and a vacuum chamber evacuation valve 13 is provided on the vacuum chamber outer tube 11 .

[0032] The utility model also provides a cryogenic liquid intrusion pressure sensor, which is calibrated using the above-mentioned cryogenic liquid intrusion pressure sensor calibration system.

[0033] Compared with the prior art, the beneficial effects of the present invention are:

[0034] The utility model adopts a two-layer ultra-low temperature liquid cavity to form an annular nested structure. The outer annular cavity forms a temperature control cavity, and the inner cavity is a pressure control cavity required for different pressure calibrations. Its beneficial effect is that the temperature control and the pressure control are independently controlled, avoiding the adverse effect of the temperature change with the pressure change of the ultra-low temperature invasive pressure sensor under different ultra-low temperature liquid pressure controls.

[0035] The utility model adopts vacuum insulation to insulate and isolate two layers of ultra-low temperature liquid cavities into a vacuum cavity, which has the beneficial effect of reducing heat leakage during the temperature control and pressure control process of the ultra-low temperature liquid, making it easier to test the stability of temperature and pressure.

[0036] The utility model adopts vacuum insulation to insulate the test chamber of the ultra-low temperature liquid intrusion pressure sensor, and at the same time sets a radiation cold screen to further reduce radiation heat leakage. The beneficial effect is to reduce the heat leakage of the ultra-low temperature liquid intrusion pressure sensor during ultra-low temperature liquid intrusion calibration, which is convenient for increasing the number of pressure sensor calibrations and calibration time.

[0037] The utility model adopts a test cavity bellows tube to connect the test cavity top flange and the ultra-low temperature test bench. The beneficial effect is that it can not only increase the conduction distance from the ultra-low temperature test bench to the normal temperature test cavity top flange, and reduce heat leakage from the test bench, but also can utilize the expansion and contraction of the bellows to achieve low-temperature sealing and normal-temperature sealing at the upper and lower flanges of the test cavity.

[0038] The pressure control chamber of the utility model is designed to be divided into two parts, an upper part and an lower part, which are connected by a longer neck tube. The beneficial effect is that it can form a phase separation function, avoiding the influence of gas-liquid mixing on the calibration pressure when calibrating the ultra-low temperature liquid intrusive pressure sensor at the bottom of the pressure control chamber, and at the same time greatly reducing the heat load when maintaining the temperature of the lower temperature control chamber at a fixed point.

[0039] The utility model utilizes a separately designed temperature-control chamber to provide liquid immersion cooling and temperature control only for the lower chamber. This advantageously maintains a desired temperature point for the ultra-low temperature test bench at the bottom of the lower chamber, enabling calibration testing of the pressure sensor at a fixed temperature. High-precision temperature control eliminates conventional heat conduction-based cooling and heating temperature control. By leveraging the one-to-one correspondence between the saturation temperature and saturation pressure of ultra-low temperature liquids, the temperature-control chamber controls the liquid pressure within the chamber to achieve more precise temperature regulation.

[0040] The pressure control method design of the pressure-controlling chamber of the utility model adopts a larger pressure-stabilizing chamber, and sets a standard pressure sensor and a pressure-stabilizing chamber safety valve on it. The beneficial effect is that in the process of controlling the pressure of the pressure-stabilizing chamber, the safe use and discharge of the pressure in the pressure-stabilizing chamber are ensured, and the outlet pressure of the pressure reducing valve is determined and checked to meet the calibration requirements.

[0041] The pressure control method of the pressure control chamber of the utility model also adopts a flow controller and a gas proportional valve. The beneficial effect is that the opening adjustment of the flow controller and the gas proportional valve is finely controlled to release the vaporized gas of the ultra-low temperature fluid caused by the additional heat load brought about by the gas pressurization process, thereby achieving high-precision pressurization at different pressures at low temperatures.

[0042] The utility model can not only avoid the influence of gas-liquid mixing on the output pressure, but also realize different pressure calibration tests maintained at a fixed temperature to meet the research and calibration needs of ultra-low temperature liquid intrusive pressure sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a schematic diagram of a calibration system for an ultra-low temperature liquid intrusive pressure sensor according to an embodiment of the present utility model. DETAILED DESCRIPTION

[0044] In order to facilitate those skilled in the art to understand the technical solution of the present invention, the technical solution of the present invention is further described in conjunction with the accompanying drawings.

[0045] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0046] See also Figure 1 As shown, the present invention provides a calibration system for an ultra-low temperature liquid invasive pressure sensor, comprising a vacuum insulation chamber 10, a temperature control chamber assembly 20, a pressure control chamber assembly 30, a pressure control gas assembly 40, a standard differential pressure gauge 50 and a test chamber assembly 60.

[0047] In this embodiment, the vacuum insulation chamber 10 includes a vacuum chamber outer cylinder 11 and a vacuum chamber flange cover 12. The vacuum chamber flange cover 12 and the vacuum chamber outer cylinder 11 are detachably and hermetically connected. A vacuum chamber evacuation valve 13 is provided on the vacuum chamber outer cylinder 11. When the vacuum chamber outer cylinder 11 and the vacuum chamber flange cover 12 are sealed, the vacuum insulation chamber 10 can be evacuated through the vacuum chamber evacuation valve 13. This helps to insulate the temperature control chamber 21 and the pressure control chamber 31, which contain ultracold liquid, within the vacuum insulation chamber 10.

[0048] In this embodiment, the temperature-controlled chamber assembly 20 includes a temperature-controlled chamber 21, a temperature-controlled chamber liquid inlet pipeline, and a temperature-controlled chamber exhaust pipeline. The temperature-controlled chamber 21 is located within the vacuum insulation chamber 10. The temperature-controlled chamber liquid inlet pipeline and the temperature-controlled chamber exhaust pipeline pass through the vacuum chamber flange cover 12 and communicate with the temperature-controlled chamber 21. Furthermore, a temperature-controlled chamber liquid inlet valve 22 is provided on the temperature-controlled chamber liquid inlet pipeline, and a temperature-controlled chamber exhaust valve 23 is provided on the temperature-controlled chamber exhaust pipeline. The temperature-controlled chamber liquid inlet valve 22 and the temperature-controlled chamber exhaust valve 23 achieve balanced inflow and outflow of ultra-cold liquid, thereby achieving pressure stability in the temperature-controlled chamber 21 and thereby achieving temperature stability within the temperature-controlled chamber 21, thereby achieving the temperature control purpose of the temperature-controlled chamber 21.

[0049] In this embodiment, the temperature control chamber 21 is in the shape of an inverted concave character, and a mounting opening is provided in the central concave portion.

[0050] In this embodiment, the pressure control chamber assembly 30 includes a pressure control chamber 31, a pressure control chamber liquid inlet pipeline, and a pressure control chamber exhaust pipeline. The pressure control chamber 31 includes an upper cavity 311, a long neck tube 312, and a lower cavity 313. The two ends of the long neck tube 312 are connected to the upper cavity 311 and the lower cavity 313 respectively. The temperature control chamber 21 and the pressure control chamber 31 are located in the vacuum insulation chamber 10, and the temperature control chamber 21 wraps the lower cavity 313, and the test chamber assembly 60 is connected to the lower cavity 313. The pressure control chamber liquid inlet pipeline and the pressure control chamber exhaust pipeline pass through the vacuum chamber flange cover 12 and are connected to the upper cavity 311. The lower cavity 313 partially protrudes from the installation port of the temperature control chamber 21 to form a test platform installation port.

[0051] In this embodiment, a pressure control chamber pressure sensor 321 and a pressure control chamber liquid inlet valve 322 are further provided on the pressure control chamber liquid inlet pipeline, and a gas proportional valve 331, a flow controller 332 and a pressure control chamber safety valve 333 are sequentially provided on the pressure control chamber exhaust pipeline.

[0052] In this embodiment, the pressure control chamber 31 is designed to be connected by a longer neck tube in the middle of the upper and lower chambers, and the lower chamber 313 is connected to the ultra-low temperature test bench 62 through a low-temperature seal. This connection can achieve low-temperature and high-pressure sealing of ultra-low temperature liquid.

[0053] In this embodiment, the pressure-control gas assembly 40 includes a pressure-control gas inlet pipe 41, a pressure-stabilizing chamber 42, a high-pressure helium cylinder 43, a pressure-reducing valve 44, a pressure-stabilizing chamber safety valve 45, and a pressure-stabilizing chamber pressure sensor 46. The two ends of the pressure-control gas inlet pipe 41 connect the pressure-stabilizing chamber 42 and the upper chamber 311, respectively. The outlet of the high-pressure helium cylinder 43 connects to the pressure-stabilizing chamber 42. The pressure-reducing valve 44 is located in the pipeline connecting the high-pressure helium cylinder 43 and the pressure-stabilizing chamber 42. The pressure-reducing valve 44 and the pressure-stabilizing chamber safety valve 45 are connected to the pressure-stabilizing chamber 42.

[0054] In this embodiment, the outlet of the high-pressure helium cylinder 43 is connected to the pressure reducing valve 44 and then to the pressure stabilizing chamber 42 via a gas pipeline. The outlet of the pressure stabilizing chamber 42 is connected to the pressure-controlled air inlet pipeline 41, which is connected to the upper chamber 311 via the vacuum chamber flange cover 12, thus forming a pressure air inlet pipeline. The gas proportional valve 331 and the flow controller 332 are also connected to the upper chamber 311 via the vacuum chamber flange cover 12. In this way, a pressure exhaust pipeline can be formed by setting the flow controller 332 of the pressure air inlet pipeline and adjusting the opening of the gas proportional valve 331. Through the comprehensive adjustment of the air intake of the pressure-controlled air inlet pipeline and the exhaust of the pressure exhaust pipeline, the pressure in the pressure-controlled chamber 31 is stabilized. The pressure-controlled chamber liquid inlet valve 322 is used to replenish the ultra-cold liquid in the pressure-controlled chamber 31, and the pressure-controlled chamber safety valve 333 is used to ensure the strength and safety of the pressure-controlled chamber 31.

[0055] In this embodiment, the standard differential pressure gauge 50 is connected to the upper cavity 311. The standard differential pressure gauge 50 and the pressure control cavity pressure sensor 321 respectively test the gas pressure and liquid pressure of the gas space in the upper cavity 311, and the sum of the two is used as the calibration comparison pressure.

[0056] In this embodiment, the test chamber assembly 60 includes a test chamber bellows 61, a cryogenic test platform 62, a test chamber top flange 63, a test chamber radiation shield hanging rod 64, a test chamber radiation shield 65, and a test chamber evacuation valve 66. A test installation port is provided at the bottom of the vacuum chamber outer tube 11, and the cryogenic test platform 62 is secured to the test platform installation port via a detachable sealing flange at the test installation port.

[0057] In this embodiment, the test cavity bellows tube 61 is connected to the inner recess of the temperature control cavity 21 through a test installation port, and the test cavity top flange 63 is detachably connected to the other end of the test cavity bellows tube 61. The inner recess of the temperature control cavity 21, the test cavity bellows tube 61, the ultra-low temperature test bench 62 and the test cavity top flange 63 enclose and form a test cavity 67. The pressure sensor to be calibrated is installed on the ultra-low temperature test bench 62. The test end of the pressure sensor A to be calibrated, that is, the test port, is located in the lower cavity 313. The non-test end, that is, the data line connection end of the pressure sensor A, is located in the test cavity 67. The lower cavity 313 is filled with ultra-low temperature liquid. The test end of the pressure sensor to be calibrated is in direct contact with the ultra-low temperature liquid, forming an ultra-low temperature liquid intrusion pressure test. In addition, during calibration, multiple ultra-low temperature liquid intrusion pressure sensors can be calibrated simultaneously.

[0058] In this embodiment, a test chamber radiation shield hanging rod 64 is fixedly connected to the test chamber top flange 63. Multiple test chamber radiation shields 65 are fixed to the test chamber top flange 63. The test chamber top flange 63 and the test chamber radiation shields 65 are located within a test chamber 67. Furthermore, a pipeline containing a test chamber evacuation valve 66 passes through the test chamber top flange 63 and communicates with the test chamber 67.

[0059] In this embodiment, test chamber 67 is evacuated via test chamber evacuation valve 66, achieving a vacuum insulation effect after the pressure sensor to be calibrated is installed within test chamber 67. Multiple test chamber radiation shields 65 are secured to test chamber top flange 63 via test chamber radiation shield hanging rods 64. This reduces radiation heat leakage from the pressure sensor to be calibrated within test chamber 67. The test chamber radiation shield hanging rods 64 are typically made of a non-metallic material with low thermal conductivity. The test chamber radiation shields 65 are constructed of 0.5 mm thick stainless steel sheets with a mirror finish to reduce radiation heat leakage from the ultra-low temperature test bench 62.

[0060] In this embodiment, the lower cavity 313 is immersed in the low-temperature fluid in the temperature-controlled cavity 21, so that the temperature of the lower cavity 313 including the ultra-low temperature test bench 62 is completely consistent with the temperature of the temperature-controlled cavity 21, thereby ensuring the constancy of the test temperature of the invasive pressure sensor and not being affected by changes in its test pressure.

[0061] See also Figure 1 As shown, in one embodiment of the present invention, during use, the test chamber top flange 63 is opened, the ultra-low temperature test bench 62 is exposed to the atmosphere, and the pressure sensor to be calibrated is mounted on the ultra-low temperature test bench 62. After the pressure sensor to be calibrated is installed, the test chamber top flange 63, on which the test chamber radiation shield 65 is mounted, is sealed and mounted, and the test chamber 67 is evacuated via the test chamber evacuation valve 66. After the test chamber 67 is evacuated, the vacuum insulation chamber 10 is evacuated via the vacuum chamber evacuation valve 13. After the vacuum insulation chamber 10 is evacuated, ultra-cold liquid is added to the temperature control chamber 21 via the temperature control chamber liquid inlet valve 22. The temperature control chamber exhaust valve 23 is opened to ensure that the pressure in the temperature control chamber 21 reaches the saturation pressure at the desired test temperature, thereby achieving the desired test temperature within the temperature control chamber 21. Simultaneously, after the vacuum insulation chamber 10 is evacuated, ultra-cold liquid is injected into the pressure control chamber 31, and the temperature control chamber 21 is evacuated. When the ultra-cold liquid level reaches the bottom of the upper chamber 311, the injection of ultra-cold liquid is stopped. Specifically, after the vacuum insulation chamber 10 is evacuated, the flow controller 332 and the gas proportional valve 331 are adjusted to the fully open position, the pressure control chamber liquid inlet valve 322 is opened, and the ultra-cold liquid is added to the pressure control chamber 31. After the pressure control chamber 31 is filled with ultra-cold liquid, the pressure control chamber liquid inlet valve 322 is closed, and then the high-pressure helium cylinder 43 is opened. The pressure reducing valve 44 is adjusted to reduce the pressure to the required test pressure. Through the intake of gas through the pressure control inlet pipe 41 and the valve opening of the flow controller 332 and the gas proportional valve 331, an inlet and outlet gas balance is established, thereby achieving the target pressure control in the pressure control chamber 31 and meeting the test conditions of the ultra-cold liquid invasive pressure sensor.

[0062] The utility model also provides a cryogenic liquid intrusion pressure sensor, which is calibrated using the above-mentioned cryogenic liquid intrusion pressure sensor calibration system.

[0063] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the foregoing description. It is intended that all variations within the meaning and range of equivalents of the claims be encompassed within the present invention, and any reference numerals in the claims should not be construed as limiting the claims to which they relate.

[0064] The above-mentioned embodiments only represent the implementation methods of the utility model. The protection scope of the utility model is not limited to the above-mentioned embodiments. For those skilled in the art, several modifications and improvements can be made without departing from the concept of the utility model, which all fall within the protection scope of the utility model.

Claims

1. A calibration system for ultra-low temperature liquid invasive pressure sensors, characterized in that: include: A vacuum insulation chamber (10), a temperature control chamber assembly (20), a pressure control chamber assembly (30), a pressure control gas assembly (40), a standard differential pressure gauge (50), and a test chamber assembly (60); The pressure control chamber assembly (30) comprises a pressure control chamber (31), a pressure control chamber liquid inlet pipeline and a pressure control chamber exhaust pipeline; Furthermore, the pressure control chamber (31) includes an upper chamber (311), a long neck tube (312), and a lower chamber (313); both ends of the long neck tube (312) are respectively connected to the upper chamber (311) and the lower chamber (313); The temperature control chamber assembly (20) wraps the lower chamber (313), and the ultra-low temperature test bench (62) in the test chamber assembly (60) is connected to the lower chamber (313); The pressure control chamber liquid inlet pipeline, the pressure control chamber exhaust pipeline, and the pressure control gas component (40) pass through the vacuum insulation chamber (10) and are communicated with the upper chamber (311); A standard differential pressure gauge (50) is connected to the upper cavity (311), and a pressure control cavity pressure sensor (321) is provided on the pressure control cavity liquid inlet pipeline. The gas pressure and liquid pressure of the gas space in the upper cavity (311) are respectively tested by the standard differential pressure gauge (50) and the pressure control cavity pressure sensor (321), and the sum of the two is used as the calibration comparison pressure.

2. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 1, characterized in that: The temperature control chamber assembly (20) includes a temperature control chamber (21), and the temperature control chamber (21) is in an inverted concave shape, and a mounting opening is provided at the central concave portion; the lower cavity (313) part protrudes from the mounting opening to form a test platform mounting opening.

3. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 2, characterized in that: The temperature control chamber assembly (20) includes a temperature control chamber liquid inlet pipeline and a temperature control chamber exhaust pipeline; the temperature control chamber liquid inlet pipeline and the temperature control chamber exhaust pipeline are both connected to the temperature control chamber (21), and a temperature control chamber liquid inlet valve (22) is provided on the temperature control chamber liquid inlet pipeline, and a temperature control chamber exhaust valve (23) is provided on the temperature control chamber exhaust pipeline.

4. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 1, characterized in that: A pressure control chamber liquid inlet valve (322) is also provided on the pressure control chamber liquid inlet pipeline; and a gas proportional valve (331) and a flow controller (332) are sequentially provided on the pressure control chamber exhaust pipeline.

5. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 2, characterized in that: The test chamber assembly (60) includes a test chamber bellows tube (61) and a test chamber top flange (63); A test installation opening is provided at the bottom of the vacuum insulation chamber (10), and the ultra-low temperature test table (62) is fixed to the test platform installation opening via a detachable sealing flange of the test installation opening; The test cavity bellows tube (61) is connected to the inner concave portion of the temperature control cavity (21) through the test installation port at one end; the test cavity top flange (63) is detachably connected to the other end of the test cavity bellows tube (61); The inner concave portion of the temperature control cavity (21), the test cavity bellows tube (61), the ultra-low temperature test table (62) and the test cavity top flange (63) are enclosed to form a test cavity (67).

6. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 5, characterized in that: The test chamber assembly (60) includes a test chamber radiation screen hanging rod (64), a test chamber radiation screen (65) and a test chamber evacuation valve (66); A test chamber radiation screen hanging rod (64) is fixedly connected to the test chamber top flange (63), a plurality of test chamber radiation screens (65) are fixed on the test chamber top flange (63), and the test chamber top flange (63) and the test chamber radiation screens (65) are located in the test chamber (67); and a pipeline where the test chamber evacuation valve (66) is located passes through the test chamber top flange (63) and is communicated with the test chamber (67).

7. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 1, characterized in that: The pressure-controlled gas assembly (40) includes a pressure-controlled gas inlet pipe (41), a pressure-stabilizing chamber (42) and a high-pressure helium cylinder (43); The two ends of the pressure-controlled air inlet pipe (41) are respectively connected to the pressure-stabilizing chamber (42) and the upper chamber (311), and the outlet of the high-pressure helium bottle (43) is connected to the pressure-stabilizing chamber (42).

8. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 7, characterized in that: The pressure-control gas assembly (40) includes a pressure reducing valve (44), a pressure stabilizing chamber safety valve (45), and a pressure stabilizing chamber pressure sensor (46); the pressure reducing valve (44) is located on a pipeline connecting the high-pressure helium cylinder (43) and the pressure stabilizing chamber (42), and the pressure reducing valve (44) and the pressure stabilizing chamber safety valve (45) are connected to the pressure stabilizing chamber (42).

9. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 1, characterized in that: The vacuum insulation chamber (10) comprises a vacuum chamber outer cylinder (11) and a vacuum chamber flange cover (12); the vacuum chamber flange cover (12) and the vacuum chamber outer cylinder (11) are detachably sealed, and a vacuum chamber evacuation valve (13) is provided on the vacuum chamber outer cylinder (11).

10. A cryogenic liquid intrusion pressure sensor, characterized in that: Calibration is performed using the ultra-low temperature liquid intrusive pressure sensor calibration system described in any one of claims 1 to 9.

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