Low-temperature supercooling perforated plate flow measuring device

Abstract

A low-temperature supercooling perforated plate flow measuring device is characterized in that a liquid nitrogen supply device is communicated and connected with a low-temperature supercooling device, a measuring system is in electric signal connection with the low-temperature supercooling device, and high-pressure and high-temperature liquid nitrogen in a pipeline exchanges heat with normal-pressure and low-temperature liquid nitrogen in a normal-pressure liquid nitrogen storage tank through a coil heat exchanger; and the high-pressure liquid nitrogen in the pipeline is subjected to normal-pressure liquid nitrogen evaporation and heat absorption so as to be converted into a supercooled state, so that the saturated vapor pressure of the high-pressure liquid nitrogen is reduced, the differential pressure flowmeter has higher pressure drop margin when being used for throttling and depressurizing flow measurement, and cavitation is reduced. Key physical parameters such as the temperature and pressure of fluid in a pipeline and orifice plate throttling pressure difference can be obtained in one experiment, the problem that gas-liquid two-phase flow is prone to occurring when the low-temperature fluid is measured through a differential pressure type flowmeter is solved, and accurate measurement of the flow of the low-temperature fluid is achieved; the device can be applied to flow measurement of low-temperature fluid such as low-temperature liquid nitrogen and liquid oxygen.

Description

Technical Field

[0001] This invention relates to the field of cryogenic fluid flow measurement technology, specifically a cryogenic subcooled orifice plate flow measurement device. Background Technology

[0002] Currently, traditional orifice plate flow meters are widely used for measuring the flow of gases, liquids, and steam due to their simple structure, convenient maintenance, stable performance, absence of any moving parts, and safe and reliable operation.

[0003] Among them, the multi-orifice plate flowmeter, while inheriting the advantages of the standard orifice plate flowmeter, can balance and adjust the flow field due to its multi-orifice structure, which can significantly reduce eddies, alleviate dead zone effects, reduce fluid pressure loss, and effectively prevent cavitation, making it more suitable for measuring low-temperature fluids.

[0004] However, cryogenic fluids such as liquid nitrogen and liquid hydrogen have high saturated vapor pressures and easily evaporate to produce gas at atmospheric pressure. After being throttled by an orifice plate, these gases readily generate a two-phase flow, which reduces the accuracy of the flow meter to some extent. Therefore, it is necessary to propose a cryogenic subcooled orifice plate flow measurement device to monitor and reduce the occurrence of cavitation in cryogenic liquid nitrogen in real time. Summary of the Invention

[0005] To address the aforementioned shortcomings in existing technologies, the present invention aims to provide a low-temperature subcooled orifice plate flow measurement device. This device solves the problem that existing saturated vapor pressures are high, and the vapor easily evaporates to produce gas at normal pressure. After being throttled by the orifice plate, the gas-liquid two-phase flow is easily generated, which reduces the accuracy of flow meter measurements to a certain extent.

[0006] The technical solution adopted by the present invention to achieve the above-mentioned objective is: a cryogenic subcooled orifice plate flow measurement device, comprising a liquid nitrogen supply device and a cryogenic subcooling device, wherein the liquid nitrogen supply device and the cryogenic subcooling device are connected in communication, characterized in that: the liquid nitrogen supply device includes a liquid nitrogen storage tank and a self-pressurizing liquid nitrogen storage tank; the liquid nitrogen storage tank and the self-pressurizing liquid nitrogen storage tank are connected by a cryogenic liquid stainless steel corrugated hose; a cryogenic regulating valve and a cryogenic shut-off valve are further provided between the liquid nitrogen storage tank and the self-pressurizing liquid nitrogen storage tank, wherein the cryogenic regulating valve and the cryogenic shut-off valve are respectively The cryogenic subcooling device is mounted on a cryogenic liquid stainless steel corrugated hose. It includes a cryogenic vent valve, an insulation cover, a coiled heat exchanger, and an atmospheric pressure liquid nitrogen storage tank. The atmospheric pressure liquid nitrogen storage tank is mounted on the cryogenic liquid stainless steel corrugated hose, with the insulation cover movably connected to the top of the tank. The coiled heat exchanger is located inside the atmospheric pressure liquid nitrogen storage tank, and the cryogenic vent valve is located at the center of the top of the tank. The measurement system includes a measurement module and a data acquisition module, which are connected by an electrical signal.

[0007] To further improve the ease of use of the cryogenic subcooled perforated plate flow measurement device, the present invention adopts the following solution: the measurement module includes a temperature sensor, a pressure sensor, a differential pressure sensor, and a perforated plate flow meter. The perforated plate flow meter is connected to the cryogenic liquid stainless steel corrugated hose and is located between the self-pressurized liquid nitrogen storage tank and the self-pressurized liquid nitrogen storage tank. The temperature sensor, the pressure sensor, and the differential pressure sensor are sequentially connected to the perforated plate flow meter for electrical signal connection.

[0008] To further improve the ease of use of the low-temperature subcooled orifice plate flow measurement device, the present invention adopts the following solution: the temperature sensor is a platinum resistance temperature sensor, and the model parameters of the platinum resistance temperature sensor include PT100, PT1000 and PT10.

[0009] To further improve the ease of use of the low-temperature subcooled perforated plate flow measurement device, the present invention adopts the following solution: the pressure sensor is a strain gauge pressure sensor, and the model parameters of the strain gauge pressure sensor include XJC-Y18Y, FP110 and SLH700.

[0010] To further improve the ease of use of the low-temperature subcooled perforated plate flow measurement device, the present invention adopts the following solution: the differential pressure sensor is a microelectromechanical system (MEMS) sensor, and the model parameters of the MEMS sensor include FS8001, FS8003 and SCHA63T-K03.

[0011] To further improve the ease of use of the low-temperature subcooled orifice plate flow measurement device, the present invention adopts the following solution: the low-temperature regulating valve and the low-temperature liquid stainless steel corrugated hose are connected by a compression fitting; the low-temperature shut-off valve and the low-temperature liquid stainless steel corrugated hose are connected by a thread.

[0012] To further improve the ease of use of the cryogenic subcooled perforated plate flow measurement device, the present invention adopts the following solution: a pressure gauge for monitoring pressure is connected to the liquid nitrogen storage tank.

[0013] The present invention also provides a low-temperature subcooled orifice plate flow measurement system, characterized in that: the measurement system is connected to the low-temperature subcooling device, and includes a measurement module, a measurement controller, an identification robot and a data acquisition module; the measurement module and the measurement controller constitute a measurement unit module; several measurement unit modules are connected to the identification robot by electrical signals; and the identification robot is connected to the data acquisition module by electrical signals.

[0014] To further improve the ease of use of the low-temperature subcooled perforated plate flow measurement system, the present invention adopts the following solution: the data acquisition module includes a data acquisition instrument and a NIST database installed within the data acquisition instrument; one end of the data acquisition instrument is provided with an input module, and the other end of the data acquisition instrument is provided with an output module.

[0015] To further improve the ease of use of the low-temperature subcooled perforated plate flow measurement system, the present invention adopts the following solution: The input module includes a calculation module and a communication transmission module. The calculation module calculates the measurement information based on the identification robot and the flow information input through the input module, and is used to digitally convert and record the location of the measured flow. The output module includes a data verification module and a storage module. The data verification module is used to filter abnormal data, and the storage module is used for real-time retention and synchronous sharing of the respective measurement data.

[0016] The beneficial effects of this invention are:

[0017] (i) By setting up a low-temperature regulating valve and a low-temperature shut-off valve, this case can effectively stabilize the flow rate of fluid in the pipe and ensure experimental safety.

[0018] (ii) By using a low-temperature liquid stainless steel bellows, the experimental device can be more easily installed and disassembled, and the structure can be more compact, reducing the floor space required.

[0019] (iii) The low-temperature supercooling device in this case can effectively reduce the temperature of the high-pressure liquid nitrogen in the tube, thereby reducing the generation of gas phase and improving the measurement accuracy.

[0020] (iv) The insulation cover design in this case is not only easy to disassemble, but also effectively reduces heat loss and liquid nitrogen loss. At the same time, the low-temperature exhaust valve also has the function of maintaining the pressure inside the tank.

[0021] (v) Through the arrangement of the measurement module and the data acquisition module, this case can realize the automatic acquisition of data, and query the physical property parameters based on the measured data values ​​to accurately measure the liquid nitrogen flow rate.

[0022] In addition, the measurement system provided by this invention can effectively combine measurement devices, reduce hardware costs, improve measurement accuracy, and meet the needs of multi-orifice plate flowmeters for real-time monitoring and accurate early warning of orifice flow based on the inheritance of standard orifice plate flowmeters. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of an experimental scenario in an embodiment of the present invention;

[0024] Figure 2 This is a three-dimensional structural diagram of the low-temperature subcooling device of the present invention;

[0025] Figure 3 This is a top view of the low-temperature subcooling device of the present invention;

[0026] Figure 4 This is a schematic diagram of the main structure of the low-temperature subcooling device of the present invention;

[0027] Figure 5 for Figure 4 A schematic diagram of the cross-section along the AA direction;

[0028] Figure 6 This is a module framework diagram of the measurement system in an embodiment of the present invention;

[0029] Figure 7 This is a partial module framework in an embodiment of the present invention. Figure 1 ;

[0030] Figure 8 This is a partial module framework in an embodiment of the present invention. Figure 2 ;

[0031] Figure 9 This is a partial module framework in an embodiment of the present invention. Figure 3 .

[0032] In the diagram: 1. Liquid nitrogen storage tank; 2. Pressure gauge; 3. Cryogenic regulating valve; 4. Cryogenic shut-off valve; 5. Cryogenic liquid stainless steel corrugated hose; 6. Cryogenic exhaust valve; 7. Insulated cover plate; 8. Coil heat exchanger; 9. Atmospheric pressure liquid nitrogen storage tank; 10. Temperature sensor; 11. Pressure sensor; 12. Differential pressure sensor; 13. Orifice plate flow meter; 14. Self-pressurizing liquid nitrogen storage tank; 15. Data acquisition instrument; 16. NIST database. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] Please see Figure 1 The present invention provides a cryogenic subcooled perforated plate flow measurement device, comprising a liquid nitrogen supply device and a cryogenic subcooling device, wherein the liquid nitrogen supply device and the cryogenic subcooling device are connected in communication.

[0035] Please see Figures 2 to 5In this invention: the liquid nitrogen supply device includes a liquid nitrogen storage tank 1 and a self-pressurizing liquid nitrogen storage tank 14. The liquid nitrogen storage tank 1 and the self-pressurizing liquid nitrogen storage tank 14 are connected by a cryogenic liquid stainless steel corrugated hose 5. The use of a cryogenic liquid corrugated hose for pipeline connection is cryogenic, flexible, and easy to disassemble, making the overall structure more compact and reducing the footprint. A cryogenic regulating valve 3 and a cryogenic shut-off valve 4 are also provided between the liquid nitrogen storage tank 1 and the self-pressurizing liquid nitrogen storage tank 14. The cryogenic regulating valve 3 and the cryogenic shut-off valve 4 are sequentially arranged on the cryogenic liquid stainless steel corrugated hose 5. The self-pressurizing liquid nitrogen storage tank 14 can collect liquid nitrogen in the experiment and discharge liquid nitrogen for other uses through self-pressurization. The cryogenic subcooling device includes a cryogenic exhaust valve 6, an insulation cover plate 7, a coil heat exchanger 8, and a normal temperature control system. A pressurized liquid nitrogen storage tank 9 is mounted on a cryogenic liquid stainless steel corrugated hose 5. The top of the pressurized liquid nitrogen storage tank 9 is movably connected to an insulation cover plate 7. The insulation cover plate 7 is equipped with a cryogenic vent valve 6 and contains internal insulation foam. Its outer diameter is larger than that of the pressurized liquid nitrogen storage tank 9, and its inner diameter is approximately equal to the diameter of the tank opening. It is sealed by its own weight to reduce heat exchange with the outside environment. A coil-type heat exchanger 8 is placed inside the pressurized liquid nitrogen storage tank 9. The cryogenic vent valve 6 is located at the center of the top of the pressurized liquid nitrogen storage tank 9 and is threadedly connected to the insulation cover plate 7. During the experiment, the cryogenic vent valve is opened to maintain the pressure inside the tank. The measurement system includes a measurement module and a data acquisition module, which are connected by an electrical signal. Cryogenic liquid nitrogen enters the subcooling system after being stabilized by the cryogenic regulating valve from the liquid nitrogen supply system. Atmospheric pressure liquid nitrogen is used to subcool the high-pressure liquid nitrogen in the pipeline. Based on the measured temperature, pressure and pressure difference, the liquid nitrogen properties under this condition are queried using NIST software, and the liquid nitrogen flow rate is calculated.

[0036] Furthermore, the cryogenic exhaust valve 6 is connected to the insulation cover plate 7 via threads to discharge the evaporated liquid nitrogen in the atmospheric pressure liquid nitrogen storage tank 9, maintaining the pressure inside the tank. The inner diameter of the insulation cover plate 7 is the same as the diameter of the opening of the atmospheric pressure liquid nitrogen storage tank 9, and it fits tightly against the tank wall. It has built-in insulation foam to reduce heat exchange with the outside. Its outer diameter is slightly larger than that of the atmospheric pressure liquid nitrogen storage tank 9, and it achieves a seal with the outer edge of the insulation cover plate 7 by its own weight, reducing heat exchange. The coil heat exchanger 8 is welded to the insulation cover plate 7, which increases the weight of the insulation cover plate 7 and also improves the stability of the coil heat exchanger 8, reducing flow losses.

[0037] Furthermore, the measurement module includes a temperature sensor 10, a pressure sensor 11, a differential pressure sensor 12, and a perforated plate flow meter 13. The perforated plate flow meter 13 is connected to the cryogenic liquid stainless steel corrugated hose 5 and is located between the self-pressurized liquid nitrogen storage tank 14 and the self-pressurized liquid nitrogen storage tank 14. The temperature sensor 10, the pressure sensor 11, and the differential pressure sensor 12 are sequentially electrically connected to the perforated plate flow meter 13. The perforated plate flow meter 13 is connected by flanges on both sides, and the left flange is welded with a bare tube connecting the temperature sensor 10 and the pressure sensor 11.

[0038] Specifically, the temperature sensor 10 is a platinum resistance temperature sensor, and it is inserted into the tube through a hole and then sealed with low-temperature resin. The model parameters of the platinum resistance temperature sensor include PT100, PT1000, and PT10. The temperature collected by the above-mentioned platinum resistance temperature sensor is used to query fluid-related properties using NIST, and the liquid nitrogen flow rate is calculated based on the pressure difference.

[0039] Specifically, the pressure sensor 11 is a strain gauge pressure sensor, which measures pressure using a pressure-sensing tube connected via a clamp. The model parameters of the strain gauge pressure sensor include XJC-Y18Y, FP110, and SLH700. The pressure collected by the strain gauge pressure sensor is used to query fluid-related properties using NIST, and the liquid nitrogen flow rate is calculated based on the pressure difference.

[0040] Specifically, the differential pressure sensor 12 is a microelectromechanical system (MEMS) sensor. The differential pressure sensor 12 uses a pressure-sensing tube connected via a clamping sleeve for pressure measurement. The model parameters of the MEMS sensor include FS8001, FS8003, and SCHA63T-K03. The differential pressure collected by the MEMS sensor is used to query fluid-related properties using NIST, and the liquid nitrogen flow rate is calculated based on the differential pressure.

[0041] Furthermore, the data acquisition module includes a data acquisition instrument 15 and a NIST database 16. The data acquisition module uses an Agilent 34970A data acquisition instrument to collect physical parameters such as liquid nitrogen temperature, pressure, and pressure difference in real time, and queries the NIST database to query the physical properties of liquid nitrogen under this state, thereby accurately calculating the liquid nitrogen flow rate.

[0042] Furthermore, the cryogenic regulating valve 3 and the cryogenic liquid stainless steel corrugated hose 5 are connected by a compression fitting; the cryogenic shut-off valve 4 and the cryogenic liquid stainless steel corrugated hose 5 are connected by a thread.

[0043] Furthermore, a pressure gauge 2 is connected to the liquid nitrogen storage tank 1 to monitor the pressure of the liquid nitrogen storage tank 1.

[0044] On the other hand, such as Figures 6 to 9 As shown, this embodiment provides a low-temperature subcooled orifice plate flow measurement system. The system is characterized by being connected to a low-temperature subcooling device and includes a measurement module, a measurement controller, an identification robot, and a data acquisition module. The measurement module and the measurement controller constitute a measurement unit module. Several measurement unit modules are electrically connected to the identification robot, and the identification robot is electrically connected to the data acquisition module. The measurement system provided by this invention effectively integrates the measurement device, reduces hardware costs, improves measurement accuracy, and meets the needs of orifice plate flow meters for real-time monitoring and accurate early warning of orifice flow, building upon the foundation of standard orifice plate flow meters.

[0045] Furthermore, the data acquisition module includes a data acquisition device 15 and a NIST database 16 installed within the data acquisition device 15. One end of the data acquisition device 15 is provided with an input module, and the other end of the data acquisition device 15 is provided with an output module.

[0046] The input module includes a calculation module and a communication transmission module. The calculation module calculates measurement information based on the identification robot and the flow information input through the input module, and is used to digitally convert and record the location of the measured flow.

[0047] The output module includes a data verification module and a storage module. The data verification module is used to filter out abnormal data, and the storage module is used for real-time retention and synchronous sharing of the measurement data.

[0048] This invention improves the liquid nitrogen subcooling process, reducing the problem of inaccurate measurements caused by the formation of gas-liquid two-phase flow when cryogenic fluids flow through differential pressure flowmeters. It utilizes cryogenic liquid nitrogen from an atmospheric pressure liquid nitrogen storage tank, and subcools the high-pressure, high-temperature liquid nitrogen in the pipeline via a heat exchanger. This lowers the temperature of the high-pressure liquid nitrogen, reducing its saturated vapor pressure and minimizing cavitation after orifice plate throttling, thus ensuring accurate flow measurement.

[0049] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here. The contents not described in detail in this specification belong to the prior art known to those skilled in the art.

[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A low-temperature supercooling porous plate flow measuring device comprising a liquid nitrogen supply device and a low-temperature supercooling device, the liquid nitrogen supply device and the low-temperature supercooling device being connected in communication through a piping connection, characterized by: The liquid nitrogen supply device comprises a liquid nitrogen storage tank (1) and a self-pressurized liquid nitrogen storage tank (14), the liquid nitrogen storage tank (1) and the self-pressurized liquid nitrogen storage tank (14) are connected in communication through a low-temperature liquid stainless steel corrugated hose (5); a low-temperature regulating valve (3) and a low-temperature stop valve (4) are further arranged in sequence between the liquid nitrogen storage tank (1) and the self-pressurized liquid nitrogen storage tank (14), the low-temperature regulating valve (3) and the low-temperature stop valve (4) are both installed on the low-temperature liquid stainless steel corrugated hose (5); the low-temperature supercooling device comprises a low-temperature exhaust valve (6), a heat preservation cover plate (7), a coil type heat exchanger (8) and an atmospheric pressure liquid nitrogen storage tank (9), the atmospheric pressure liquid nitrogen storage tank (9) is arranged on the low-temperature liquid stainless steel corrugated hose (5), the top end of the atmospheric pressure liquid nitrogen storage tank (9) is movably connected with the heat preservation cover plate (7), the coil type heat exchanger (8) is arranged in the atmospheric pressure liquid nitrogen storage tank (9), and the low-temperature exhaust valve (6) is arranged at the center of the top of the atmospheric pressure liquid nitrogen storage tank (9).

2. A subcooled porous-plate flow measurement device of claim 1, wherein: Further comprising a measuring module, the measuring module comprises a temperature sensor (10), a pressure sensor (11), a differential pressure sensor (12) and a perforated plate flowmeter (13), the perforated plate flowmeter (13) is connected on the low-temperature liquid stainless steel corrugated hose (5) and located between the self-pressurized liquid nitrogen storage tank (14) and the self-pressurized liquid nitrogen storage tank (14), and the temperature sensor (10), the pressure sensor (11) and the differential pressure sensor (12) are connected with the perforated plate flowmeter (13) through electrical signals.

3. A subcooled cryogenic porous-plate flow measuring device according to claim 2, wherein: The temperature sensor (10) is a platinum resistance temperature sensor, and the model parameters of the platinum resistance temperature sensor include PT100, PT1000 and PT10.

4. A subcooled cryogenic porous-plate flow measuring device according to claim 2, wherein: The pressure sensor (11) is a strain pressure sensor, and the model parameters of the strain pressure sensor include XJC-Y18Y, FP110 and SLH700.

5. A subcooled cryogenic porous-plate flow measuring device according to claim 2, wherein: The differential pressure sensor (12) is a micro-electro-mechanical system (MEMS) sensor, and the model parameters of the micro-electro-mechanical system (MEMS) sensor include FS8001, FS8003 and SCHA63T-K03.

6. A subcooled cryogenic porous-plate flow measuring device according to claim 1, wherein: The low-temperature regulating valve (3) is connected with the low-temperature liquid stainless steel corrugated hose (5) through a clamping sleeve, and the low-temperature stop valve (4) is connected with the low-temperature liquid stainless steel corrugated hose (5) through a threaded connection.

7. A subcooled cryogenic porous-plate flow measuring device according to claim 1, wherein: A pressure gauge (2) for monitoring pressure is further connected to the liquid nitrogen storage tank (1).

Images