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

Abstract

The invention discloses an ultralow-temperature liquid intrusive pressure sensor calibration system and method and a sensor. The system 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. Wherein the temperature control cavity assembly comprises a temperature control cavity; 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 and the pressure control cavity are located in the vacuum heat insulation cavity, the temperature control cavity wraps the lower cavity, and 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; the standard differential pressure gauge is connected with the upper cavity, a pressure control cavity pressure sensor is arranged on the pressure control cavity liquid inlet pipeline, the gas pressure intensity and the liquid pressure intensity of the gas space in the upper cavity are respectively tested according to the standard differential pressure gauge and the pressure control cavity pressure sensor, and the sum of the gas pressure intensity and the liquid pressure intensity serves as calibration comparison pressure; according to the invention, the influence of gas-liquid mixing relative output pressure can be avoided, and different pressure calibration tests of fixed-point temperature maintenance can be realized so as to meet the research and calibration requirements of the ultralow-temperature liquid intrusive pressure sensor.

Description

Technical Field

[0001] The present invention relates to the technical field of ultra-low temperature pressure sensor pressure calibration, and in particular to an ultra-low temperature liquid intrusive pressure sensor calibration system, method and sensor. Background Art

[0002] As the main instrument for measuring pressure, pressure sensor plays an important role in the detection or testing process. When the normal temperature pressure sensor uses the pressure lead tube to measure the pressure of low temperature liquid, there will be a significant disadvantage of response lag and failure to obtain the high-frequency pulsation value of pressure.

[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 more and more widespread. These low-temperature environments have put forward higher requirements for pressure measurement. Cryogenic pressure sensors play a vital role in these fields to ensure the safety and stable operation of the system. Especially in the spacecraft cryogenic propulsion and refueling system, its harsh test conditions and working 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, thereby 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, 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, certain additional errors 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 the low-temperature pressure sensor 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 for calibration of 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 by 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 lower boiling point, which is different from the actual measured liquid working fluid.

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

[0009] When the calibration device of the ultra-low temperature liquid intrusion pressure sensor performs calibration measurement, 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 the influence of the liquid temperature gradient on the measurement and other factors, and at the same time avoid the pressure influence of the gas-liquid mixture on the output 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 invention 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 the 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] The invention patent with the patent publication number CN107941261A discloses a low-temperature test bench for sensor equipment, including a thermostat, an integrated tooling platform and a preloading device, wherein a liquid helium pool is provided in the thermostat, and the integrated tooling platform is located in 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 in the vacuum tube, the force loading control unit 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 through a flange; the outermost layer of the integrated tooling platform is a vacuum box, the vacuum box is sealed to the vacuum tube of the preloading device, a test tool for installing the sensor equipment to be tested is provided inside the vacuum box, the transmission unit in the vacuum tube is connected to the test tool, and the performance of the low-temperature sensor under continuously changing temperature can be easily measured. However, in this patent, the low-temperature pressure sensor is placed in a vacuum environment, and the test is a mechanical pressure sensor, which is essentially different from a liquid intrusive pressure sensor. Summary of the invention

[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 fluid 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 comprises: 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] Wherein, the temperature control chamber assembly 20 includes a temperature control chamber 21;

[0016] 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; and 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;

[0017] 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 chamber 313, and the test chamber assembly 60 is connected to the lower chamber 313;

[0018] 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;

[0019] The standard differential pressure gauge 50 is connected to the upper cavity 311, and a pressure control chamber pressure sensor 321 is provided on the liquid inlet pipeline of the pressure control chamber. The gas pressure and liquid pressure of the gas space in the upper cavity 311 are tested respectively according to the standard differential pressure gauge 50 and the pressure control chamber pressure sensor 321, and the sum of the two is used as the calibration comparison pressure.

[0020] In one embodiment of the present invention, 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 partially protrudes from the mounting opening to form a test platform mounting opening.

[0021] 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 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.

[0022] 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, a flow controller 332 and a pressure control chamber safety valve 333 are sequentially provided on the pressure control chamber exhaust pipeline.

[0023] In one embodiment of the present invention, the test chamber assembly 60 includes a test chamber bellows tube 61, an ultra-low temperature test table 62, and a test chamber top flange 63;

[0024] 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 through a detachable sealing flange of the test installation opening;

[0025] The test cavity bellows tube 61 is connected to the inner concave part 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;

[0026] The inner recess of the temperature control cavity 21 , the test cavity bellows 61 , the ultra-low temperature test table 62 and the test cavity top flange 63 enclose and form a test cavity 67 .

[0027] 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;

[0028] The 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 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.

[0029] In one embodiment of the present invention, the pressure-controlled gas assembly 40 includes a pressure-controlled gas inlet pipeline 41, a pressure-stabilizing chamber 42, and a high-pressure helium gas cylinder 43;

[0030] Two ends of the pressure-controlled air inlet pipeline 41 are connected to the pressure-stabilizing chamber 42 and the upper chamber 311 respectively, and the outlet of the high-pressure helium cylinder 43 is connected to the pressure-stabilizing chamber 42 .

[0031] In one embodiment of the present invention, the pressure controlling 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.

[0032] In one embodiment of the present invention, 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.

[0033] The present invention also provides a method for using a calibration system for an ultra-low temperature liquid intrusive pressure sensor, comprising:

[0034] After the pressure sensor to be tested and calibrated is installed on the test chamber assembly 60, the test chamber assembly 60 is connected to the lower chamber 313;

[0035] Evacuate the test chamber 67 in the test chamber assembly 60;

[0036] After the test chamber 67 is evacuated, the vacuum insulation chamber 10 is evacuated;

[0037] After the vacuum insulation chamber 10 is evacuated, ultra-low temperature liquid is injected into the temperature control chamber 21, and the temperature control chamber 21 is exhausted to ensure that the pressure in the temperature control chamber 21 is the saturated pressure at the required test temperature;

[0038] At the same time, after the vacuum insulation chamber 10 is evacuated, ultra-low temperature liquid is injected into the pressure control chamber 31, and the temperature control chamber 21 is exhausted. When the liquid level of the ultra-low temperature liquid is flush with the bottom of the upper cavity 311, the injection of ultra-low temperature liquid is stopped;

[0039] After the ultra-low temperature liquid is added to the pressure control chamber 31, the pressure control gas component 40 supplies gas to the pressure control chamber 31 so that the pressure inside the pressure control chamber 31 reaches the set target, and at the same time, the exhaust and intake of the pressure control chamber 31 form an inlet and outlet balance.

[0040] The present invention also provides an ultra-low temperature liquid intrusion pressure sensor, which is calibrated using the ultra-low temperature liquid intrusion pressure sensor calibration system described above.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention adopts two layers of ultra-low temperature liquid chambers 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. The beneficial effect is that the temperature control and the pressure control are independently controlled, avoiding the adverse effect of temperature changes with pressure on the ultra-low temperature invasive pressure sensor under different ultra-low temperature liquid pressure controls.

[0043] The present invention adopts vacuum insulation to insulate and isolate two layers of ultra-low temperature liquid chambers into a vacuum chamber, which has the beneficial effect of reducing heat leakage during the temperature control and pressure control process of the ultra-low temperature liquid, and facilitating the testing of temperature and pressure stability.

[0044] The invention 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 shield 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 calibration and calibration time.

[0045] The invention 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.

[0046] The pressure control chamber of the present invention 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 a phase separation function can be formed to avoid the influence of gas-liquid mixing on the calibration pressure when calibrating the ultra-low temperature liquid invasive pressure sensor at the bottom of the pressure control chamber. At the same time, it can also greatly reduce the heat load when the temperature of the lower temperature control chamber is maintained at a fixed point.

[0047] The invention uses a separately designed temperature control chamber to perform liquid immersion cooling and temperature control on the lower cavity only. The beneficial effect is that it can form a good given temperature point maintenance for the ultra-low temperature test bench at the bottom of the lower cavity, thereby realizing the calibration test of this type of pressure sensor at a fixed temperature. High-precision temperature control cancels the conventional heat conduction form of cooling and heating temperature control, and uses the one-to-one correspondence between the saturated temperature and saturated pressure of ultra-low temperature liquid. The temperature control chamber is set to control the temperature in the temperature control chamber by controlling the liquid pressure in the chamber, thereby realizing more precise temperature control.

[0048] The pressure control method of the pressure control chamber of the present invention adopts a larger pressure stabilizing chamber, and a standard pressure sensor and a pressure stabilizing chamber safety valve are arranged on it. The beneficial effect is that during the pressure control of the pressure stabilizing chamber, the safe use and discharge of the pressure in the pressure stabilizing chamber are guaranteed, and the outlet pressure of the pressure reducing valve is determined and checked to meet the calibration requirements.

[0049] The pressure control method of the pressure control chamber of the present invention also adopts a flow controller and a gas proportional valve. The beneficial effect is that fine control is achieved through the opening adjustment of the flow controller and the gas proportional valve, and the vaporized gas of the ultra-low temperature fluid caused by the additional heat load brought by the gas pressurization process can be released, thereby achieving high-precision pressurization at different pressures at low temperature.

[0050] The present invention 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 requirements of ultra-low temperature liquid invasive pressure sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Schematic diagram of a calibration system for an ultra-low temperature liquid intrusive pressure sensor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0052] 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 of the specification.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0054] 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.

[0055] In this embodiment, 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. A vacuum chamber evacuation valve 13 is provided on the vacuum chamber outer tube 11. When the vacuum chamber outer tube 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, so that the temperature control chamber 21 and the pressure control chamber 31 containing ultra-low temperature liquid in the vacuum insulation chamber 10 can be kept warm.

[0056] In this embodiment, the temperature control chamber assembly 20 includes a temperature control chamber 21, a temperature control chamber liquid inlet pipeline, and a temperature control chamber exhaust pipeline. The temperature control chamber 21 is located in the vacuum insulation chamber 10, and the temperature control chamber liquid inlet pipeline and the temperature control chamber exhaust pipeline are connected to the temperature control chamber 21 after passing through the vacuum chamber flange cover 12, 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. The temperature control chamber liquid inlet valve 22 and the temperature control chamber exhaust valve 23 are used to achieve the inflow and outflow balance of the ultra-low temperature liquid, achieve the pressure stability of the temperature control chamber 21, thereby achieving the temperature stability in the temperature control chamber 21, and thus achieving the temperature control purpose of the temperature control chamber 21.

[0057] In this embodiment, the temperature control chamber 21 is in the shape of an inverted Chinese character "C" and a mounting opening is provided in the central recess.

[0058] 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, and the two ends of the long neck tube 312 are respectively connected to the upper cavity 311 and the lower cavity 313. 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 are connected to the upper cavity 311 after passing through the vacuum chamber flange cover 12. The lower cavity 313 partially protrudes from the installation port of the temperature control chamber 21 to form a test platform installation port.

[0059] 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.

[0060] 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.

[0061] In this embodiment, the pressure control gas assembly 40 includes a pressure control air intake pipeline 41, a pressure stabilizing chamber 42, a high-pressure helium gas 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 air intake pipeline 41 are respectively connected to the pressure stabilizing chamber 42 and the upper chamber 311, and the outlet of the high-pressure helium gas cylinder 43 is connected to the pressure stabilizing chamber 42. The pressure reducing valve 44 is located on the pipeline connecting the high-pressure helium gas 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.

[0062] In this embodiment, the outlet of the high-pressure helium cylinder 43 is connected to the pressure reducing valve 44 and then connected to the pressure stabilizing chamber 42 through a gas pipeline. The outlet of the pressure stabilizing chamber 42 is connected to the pressure control air intake pipeline 41, which is connected to the upper cavity 311 through the vacuum chamber flange cover 12, thus forming a pressure air intake pipeline. The gas proportional valve 331 and the flow controller 332 are also connected to the upper cavity 311 through the vacuum chamber flange cover 12, so that a pressure exhaust pipeline can be formed by setting the flow controller 332 of the pressure air intake pipeline and adjusting the opening of the gas proportional valve 331. The pressure in the pressure control chamber 31 is stabilized by the comprehensive adjustment of the air intake of the pressure control air intake pipeline and the exhaust of the pressure exhaust pipeline. The supply of ultra-low temperature liquid in the pressure control chamber 31 is achieved through the pressure control chamber liquid inlet valve 322, and the strength safety of the pressure control chamber 31 is ensured through the pressure control chamber safety valve 333.

[0063] In this embodiment, the standard differential pressure gauge 50 is connected to the upper cavity 311. The gas pressure and liquid pressure of the gas space in the upper cavity 311 are tested respectively 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.

[0064] In this embodiment, the test chamber assembly 60 includes a test chamber bellows 61, an ultra-low temperature test platform 62, a test chamber top flange 63, a test chamber radiation screen hanging rod 64, a test chamber radiation screen 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 ultra-low temperature test platform 62 is fixed to the test platform installation port through a detachable sealing flange of the test installation port.

[0065] See also Figure 1As shown, in this embodiment, the test cavity bellows tube 61 is connected to the inner concave part of the temperature control cavity 21 through a test installation port, such as by welding, and the test cavity top flange 63 is detachably connected to the other end of the test cavity bellows tube 61. The inner concave part 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 are enclosed to form a test cavity 67. The pressure sensor to be calibrated is installed on the ultra-low temperature test bench 62, and the test end of the pressure sensor A to be calibrated, that is, the test port, is located in the lower cavity 313, and 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, and the test end of the pressure sensor to be calibrated is directly in contact with the ultra-low temperature liquid, forming an ultra-low temperature liquid intrusive pressure test. And, during calibration, multiple ultra-low temperature liquid intrusive pressure sensors can be calibrated at the same time.

[0066] In this embodiment, the 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. Furthermore, the pipeline where the test chamber evacuation valve 66 is located passes through the test chamber top flange 63 and communicates with the test chamber 67.

[0067] In this embodiment, the test chamber 67 is evacuated through the test chamber evacuation valve 66, so as to achieve the vacuum insulation effect after the pressure sensor to be calibrated is installed in the test chamber 67. The test chamber top flange 63 fixes multiple test chamber radiation screens 65 through the test chamber radiation screen hanging rod 64, so as to reduce the radiation heat leakage of the pressure sensor to be calibrated in the test chamber 67. The test chamber radiation screen hanging rod 64 is usually made of non-metallic material with low thermal conductivity, and the test chamber radiation screen 65 is made of 0.5 mm thick stainless steel sheet with mirror polishing, in order to reduce the radiation heat leakage at the ultra-low temperature test bench 62.

[0068] In this embodiment, the lower cavity 313 is immersed in the low-temperature fluid in the temperature control 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 control 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.

[0069] See also Figure 1 As shown, the present invention also provides a method for using a calibration system for an ultra-low temperature liquid intrusive pressure sensor, comprising:

[0070] S10, after the pressure sensor to be tested and calibrated is installed on the test chamber assembly 60, the test chamber assembly 60 is connected to the lower chamber 313. Specifically, 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 installed on the ultra-low temperature test bench 62.

[0071] S20, evacuate the test chamber 67 in the test chamber assembly 60. After the pressure sensor to be calibrated is installed, the test chamber top flange 63 with the test chamber radiation shield 65 is sealed and installed, and the test chamber 67 is evacuated through the test chamber evacuation valve 66.

[0072] S30, after the test chamber 67 is evacuated, the vacuum insulation chamber 10 is evacuated through the vacuum chamber evacuation valve 13.

[0073] S40, after the vacuum insulation chamber 10 is evacuated, ultra-low temperature liquid is injected into the temperature control chamber 21, and the temperature control chamber 21 is exhausted to ensure that the pressure in the temperature control chamber 21 is the saturated pressure at the required test temperature. Specifically, after the vacuum insulation chamber 10 is evacuated, ultra-low temperature liquid is injected into the temperature control chamber 21 through the temperature control chamber liquid inlet valve 22, and the temperature control chamber exhaust valve 23 is opened to ensure that the pressure in the temperature control chamber 21 is the saturated pressure at the required test temperature, thereby reaching the required test temperature in the temperature control chamber 21.

[0074] S50, at the same time, after the vacuum insulation chamber 10 is evacuated, ultra-low temperature liquid is injected into the pressure control chamber 31, and the temperature control chamber 21 is exhausted. After the liquid level of the ultra-low temperature liquid is flush with the bottom of the upper cavity 311, the injection of ultra-low temperature 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-low temperature liquid is added to the pressure control chamber 31.

[0075] S60, after the ultra-low temperature liquid is filled into the pressure control chamber 31, the pressure control gas assembly 40 supplies gas to the pressure control chamber 31, so that the pressure inside the pressure control chamber 31 reaches the set target, and at the same time, the exhaust and intake of the pressure control chamber 31 form an inlet and outlet gas balance. Specifically, after the ultra-low temperature liquid is filled into the pressure control chamber 31, the pressure control chamber liquid inlet valve 322 is closed, and then the high-pressure helium cylinder 43 is opened, and the pressure reducing valve 44 is adjusted to reduce the pressure to the required test pressure, and the inlet and outlet gas balance is formed by the intake of the pressure control inlet pipeline 41 and the setting of the flow controller 332 and the valve opening of the gas proportional valve 331, thereby realizing the target pressure control in the pressure control chamber 31 and achieving the test conditions of the ultra-low temperature liquid intrusive pressure sensor.

[0076] See also Figure 1 As shown, the present invention also provides an ultra-low temperature liquid intrusion pressure sensor, which is calibrated using the ultra-low temperature liquid intrusion pressure sensor calibration system described above.

[0077] It is obvious 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 regarded as exemplary and non-limiting from any point of view, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention, and any reference numerals in the claims should not be regarded as limiting the claims involved.

[0078] The above-described embodiments merely represent implementation methods of the invention. The protection scope of the present invention is not limited to the above-described embodiments. For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

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); Wherein, the temperature control chamber assembly (20) comprises a temperature control chamber (21); 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) comprises an upper chamber (311), a long-necked tube (312) and a lower chamber (313); two ends of the long-necked tube (312) are respectively connected to the upper chamber (311) and the lower chamber (313); The temperature control chamber (21) and the pressure control chamber (31) are located in the vacuum insulation chamber (10), the temperature control chamber (21) wraps the lower chamber (313), and the test chamber assembly (60) is connected to the lower chamber (313); The extrusion chamber liquid inlet pipeline, the extrusion chamber exhaust pipeline, and the pressure control gas component (40) pass through the vacuum insulation chamber (10) and are connected to the upper chamber body (311); A standard differential pressure gauge (50) is connected to the upper cavity (311), and a pressure control chamber pressure sensor (321) is provided on the liquid inlet pipeline of the extrusion cavity. The gas pressure and liquid pressure of the gas space in the upper cavity (311) are tested respectively by the standard differential pressure gauge (50) and the pressure control chamber 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 cavity (21) is in the shape of an inverted Chinese character "C" and is provided with a mounting opening 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 1, characterized in that: The temperature control chamber assembly (20) comprises 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); 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.

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; 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.

5. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 2, characterized in that: The test chamber assembly (60) comprises a test chamber bellows tube (61), an ultra-low temperature test bench (62) 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 bench (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 a 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 part 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) 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) comprises a test chamber radiation screen hanging rod (64), a test chamber radiation screen (65) and a test chamber evacuation valve (66); The 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 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).

7. The ultra-low temperature liquid invasive pressure sensor calibration system according to claim 1, characterized in that: The pressure-controlled gas component (40) comprises a pressure-controlled gas inlet pipeline (41), a pressure-stabilizing chamber (42) and a high-pressure helium gas cylinder (43); The two ends of the pressure-controlled air inlet pipeline (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-controlling gas assembly (40) comprises 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. A method for using a calibration system for a cryogenic liquid invasive pressure sensor according to any one of claims 1 to 8, characterized in that: include: After the pressure sensor to be tested and calibrated is installed on the test cavity assembly (60), the test cavity assembly (60) is connected to the lower cavity (313); evacuating a test chamber (67) in a test chamber assembly (60); After the test chamber (67) is evacuated, the vacuum insulation chamber (10) is evacuated; After the vacuum insulation chamber (10) is evacuated, ultra-low temperature liquid is injected into the temperature control chamber (21), and the temperature control chamber (21) is vented to ensure that the pressure in the temperature control chamber (21) is the saturation pressure at the required test temperature; At the same time, after the vacuum insulation chamber (10) is evacuated, ultra-low temperature liquid is injected into the pressure control chamber (31), and the temperature control chamber (21) is exhausted. After the liquid level of the ultra-low temperature liquid is flush with the bottom of the upper chamber (311), the injection of the ultra-low temperature liquid is stopped; After the ultra-low temperature liquid is filled into the pressure control chamber (31), the pressure control gas assembly (40) supplies gas to the pressure control chamber (31) so that the pressure inside the pressure control chamber (31) reaches a set target, and at the same time, the exhaust and intake of the pressure control chamber (31) form an inlet and outlet balance.

10. An ultra-low temperature liquid intrusive pressure sensor, characterized in that: Calibration is performed using any ultra-low temperature liquid invasive pressure sensor calibration system according to any one of claims 1 to 8.

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