Monitoring device for two-phase flow information in large belt liquid rotating gas wave oscillation tube

Abstract

The utility model discloses a device for monitoring two-phase flow information in a large belt liquid rotating gas wave oscillation tube, and belongs to the field of gas expansion refrigeration. An integrated design concept is adopted, a monitoring device for measuring two-phase flow information in the rotating pipe is designed, a sensor, a data acquisition card / wireless transmission transmitter, a microprocessor and a power supply are all arranged on a rotating shaft, synchronous rotation of all elements and the gas wave oscillation pipe is achieved, and the purpose of testing in-situ flow field information such as temperature and pressure of the gas wave oscillation pipe is achieved. The device can measure fluctuation information in straight, conical, bent and other gas wave oscillation tubes, and provides technical support for multi-aspect research on liquid adaptability of the gas wave oscillation tubes.

Description

Technical Field

[0001] The invention discloses a monitoring device for two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube, belonging to the field of gas expansion refrigeration. Background Art

[0002] Natural gas, recognized as the cleanest fossil energy in the world, plays an important role in the energy structure of various countries. With the development of my country's economy and the drive for low-carbon energy conservation, the natural gas industry will enter a sustained peak period. Direct expansion refrigeration is a common process for large-scale natural gas processing. On the one hand, it rationally utilizes the formation pressure energy, and on the other hand, it reduces the exergy loss caused by heat exchange. It is a treatment method with high energy efficiency.

[0003] When natural gas is transported through pipelines, the gas will carry a certain amount of liquid, of which about 1~7wt% is liquid alcohol injected for antifreeze. During operation, due to fluctuations in operating conditions and changes in the performance of pre-separation equipment, the amount of liquid carried by the gas can reach 20~40 wt%. In addition, when natural gas expands, the temperature decreases, condensate precipitates, and the total amount of liquid carried will increase further. In addition, with the depletion of natural gas, the content of heavy hydrocarbons and water in the gas phase will increase over time, and the liquid carrying requirements of the refrigerator will be higher. Therefore, large liquid gas expansion refrigeration has important research value and significance.

[0004] Turbine expansion and gas wave refrigeration are two typical high-efficiency gas expansion refrigeration methods. Among them, turbine expansion has the highest efficiency. Since the 1970s, people have begun to study liquid-carrying turbine expansion. After years of hard work, Air Liquide launched a liquid-carrying turbine expander with 15 wt% liquid, but expanders with a larger liquid-carrying rate are rarely reported. This is because the turbine expansion speed is generally tens of thousands or even hundreds of thousands of revolutions per minute, which makes it difficult to improve its liquid-carrying capacity. As a new method of expansion refrigeration, gas wave refrigeration mainly relies on the shock wave movement inside the gas wave oscillation tube to achieve energy exchange, does not rely on the high-speed rotation of the impeller <3000 rpm, and the oscillation tube erosion problem caused by liquid is relatively small, which makes this technology have great potential for liquid-carrying operation. However, the movement behavior of liquid-carrying gas after entering the gas wave oscillation tube is still unclear, and the liquid distribution law in the gas wave oscillation tube is still unclear. At present, it is not possible to obtain the liquid distribution law and gas fluctuation law in the rotating tube through experiments. In previous studies on the flow behavior in gas wave oscillation tubes, Dalian University of Technology, Zhejiang University, and the University of Tokyo in Japan all used the method of stationary gas wave oscillation tubes to analyze the gas fluctuation behavior in the tubes; although Nanjing University of Aeronautics and Astronautics designed a dual-channel measurement system under rotating conditions, due to the limitations of the measurement method, it did not directly measure the flow field information in the rotating tube, but instead arranged sensors on the stationary disks at both ends to obtain information used to characterize the flow field in the tube. This method cannot analyze the fluctuation behavior in large-band liquid-gas wave oscillation tubes. The lack of experimental measurement methods directly leads to the lack of data support and reference basis for the research on the phase flow behavior mechanism and two-phase refrigeration mechanism in large-band liquid rotating gas wave oscillation tubes, which limits the improvement of the refrigeration performance of large-band liquid-gas wave oscillation tubes. Therefore, how to obtain experimental data on liquid distribution and gas fluctuations in large-band liquid-gas wave oscillation tubes is one of the problems that need to be solved at present. Utility Model Content

[0005] In order to solve the above problems, the utility model proposes an experimental device and experimental method for monitoring the two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube. An integrated design concept is adopted to design an experimental device for measuring the two-phase flow information in a rotating tube. Sensors, data acquisition cards, microprocessors and power supplies are all arranged on the rotating shaft to realize synchronous operation of various components and achieve the purpose of in-situ flow field information testing of the gas wave oscillation tube.

[0006] The technical solution adopted by the utility model is: a monitoring device for two-phase flow information in a large liquid-carrying rotating air wave oscillation tube, an air intake nozzle and an exhaust nozzle are fixedly arranged on the main shaft seat of the device, the air wave oscillation tube is arranged at one end of the main shaft frame, and a static balance counterweight is arranged at the other end of the main shaft frame. The main shaft drives the air wave oscillation tube and the static balance counterweight to rotate through the main shaft frame, and the two ends of the air wave oscillation tube are matched with the air intake nozzle and the exhaust nozzle respectively;

[0007] Sensors are arranged on the outer wall surface and the inner wall surface of the air wave oscillation tube, and a light piston is arranged in the sensor connection column between the outer wall surface of the air wave oscillation tube and the sensor built-in chip; a sealing air column is arranged between the light piston and the sensor built-in chip;

[0008] The device also includes a transmission-receiving element, which includes a wired transmission-receiving element or a wireless transmission-receiving element. The wired transmission-receiving element includes a data acquisition card, a microprocessor and a mobile power supply, and the wired transmission-receiving element is fixed on the main shaft; the wireless transmission-receiving element includes a wireless transmission transmitter, a wireless transmission receiver, a memory and a controller; the wireless transmission transmitter is fixed on the main shaft; the wireless transmission receiver, the memory and the controller are placed outside the air wave oscillation tube and are fixed.

[0009] Furthermore, the light piston is made of a porous material selected from sponge and cotton.

[0010] Furthermore, the air wave oscillation tube is a straight air wave oscillation tube, a conical air wave oscillation tube or a curved air wave oscillation tube.

[0011] Furthermore, the sensor is a temperature measurement sensor, a pressure measurement sensor, a liquid film thickness measurement sensor, or a visualization measurement sensor.

[0012] Since the centrifugal force on the outer wall of the gas wave oscillation tube is the greatest when it rotates, the liquid in the large-band liquid gas wave oscillation tube will be concentrated on the outer wall due to the centrifugal force. When measuring the pressure difference between the inner and outer walls and the inner wall of the tube, the built-in chip of the sensor cannot handle gas-liquid mixed working fluids. Therefore, the utility model fills a light piston with negligible mass such as sponge, cotton and other porous materials between the outer wall liquid and the built-in chip of the sensor to reduce the influence of gas-liquid mixing on the measurement error. The utility model indirectly measures the distribution of liquid in the tube by measuring the pressure generated by the centrifugal force on the liquid, making up for the lack of technical measurement means for obtaining the distribution law of liquid in the rotating gas wave oscillation tube.

[0013] In some specific embodiments, the number of air wave oscillation tubes in the utility model patent can be a single tube or multiple tubes. The tube shape of the air wave oscillation tube includes but is not limited to straight, conical, curved, etc., and air wave oscillation tubes of various shapes can be interchangeable.

[0014] The beneficial effects of the utility model are as follows: the gas wave oscillation tube is a new device that utilizes gas fluctuations to transfer energy between gases of different pressures and realizes the expansion and refrigeration process of high-pressure gas, and has the advantages of low rotation speed and the ability to carry liquid. However, the lack of effective measurement means makes it impossible to obtain the in-situ information of the flow of liquid-carrying gas in the gas wave oscillation tube, which inhibits the expansion of the two-phase application of the gas wave oscillation tube. In response to this problem, the utility model patent adopts an integrated design concept and designs a device for measuring the two-phase flow information in a rotating tube. The sensor, data acquisition card, microprocessor and power supply are all arranged on the rotating shaft to realize the synchronous operation of each component, so as to achieve the purpose of testing the in-situ flow field information of the gas wave oscillation tube such as temperature and pressure. The device can take into account the measurement of the fluctuation information in the gas wave oscillation tube such as straight, conical, curved, etc., and provide technical support for multi-faceted research on the liquid-carrying adaptability of the gas wave oscillation tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The schematic diagram is a structural diagram of a wired transmission method for an experimental device for measuring wave information in a large-band liquid-gas wave oscillation tube.

[0016] Figure 2 The schematic diagram is a structural diagram of the wireless transmission method of an experimental device for measuring the wave information in a large-band liquid-gas wave oscillation tube.

[0017] Figure 3 Schematic diagram of the liquid barrier structure between the sensor and the large-band liquid-gas wave oscillation tube.

[0018] Figure 4 Comparison of the experimental results of pressure fluctuations on the outer and inner walls of the air wave oscillation tube, where a is without a liquid barrier structure and b is with a liquid barrier structure.

[0019] Figure 5 Schematic diagram of the experimental device of the conical large-belt liquid-gas wave oscillation tube.

[0020] Figure 6 Schematic diagram of the experimental device for the curved large-belt liquid-gas wave oscillation tube.

[0021] In the figure: 1. static balancing weight, 2. microprocessor, 3. mobile power supply, 4. data acquisition card, 5. air intake nozzle, 6. air wave oscillation tube, 6-1. outer wall of air wave oscillation tube, 6-2. inner wall of air wave oscillation tube, 6-3. conical air wave oscillation tube, 6-4. curved air wave oscillation tube, 7. sensor, 7-1. light piston, 7-2. sensor built-in chip, 8. exhaust nozzle, 9. main shaft, 9-1. main shaft frame, 10. pulley, 11. wireless transmission transmitter, 12. wireless transmission receiver, 13. memory, 14. controller. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings and specific implementation methods.

[0023] A monitoring device for two-phase flow information in a large liquid-carrying rotating air wave oscillation tube, wherein an air intake nozzle 5 and an air exhaust nozzle 8 are fixedly arranged on the main shaft seat of the device, an air wave oscillation tube 6 is arranged at one end of a main shaft frame 9-1, and a static balance counterweight 1 is arranged at the other end of the main shaft frame 9-1. The main shaft 9 drives the air wave oscillation tube 6 and the static balance counterweight 1 to rotate through the main shaft frame 9-1, and the two ends of the air wave oscillation tube 6 are respectively matched with the air intake nozzle 5 and the exhaust nozzle 8; the air wave oscillation tube 6 can be a straight air wave oscillation tube, a conical air wave oscillation tube 6-3 or a curved air wave oscillation tube 6-4. Sensors 7 are arranged on the outer wall surface 6-1 and the inner wall surface 6-2 of the air wave oscillation tube 6, and the sensor 7 is a temperature measurement sensor, a pressure measurement sensor, a liquid film thickness measurement sensor, and a visual measurement sensor. A light piston 7-1 is arranged in the sensor connection column 7-3 between the outer wall surface 6-1 of the air wave oscillation tube and the sensor built-in chip 7-2; and a sealing air column is arranged between the light piston 7-1 and the sensor built-in chip 7-2.

[0024] The device also includes a transmission-receiving element, which includes a wired transmission-receiving element or a wireless transmission-receiving element. The wired transmission-receiving element includes a data acquisition card 4, a microprocessor 2 and a mobile power supply 3. The wired transmission-receiving element is fixed on the main shaft 9; the wireless transmission-receiving element includes a wireless transmission transmitter 11, a wireless transmission receiver 12, a memory 13 and a controller 14; the wireless transmission transmitter 11 is fixed on the main shaft 9; the wireless transmission receiver 12, the memory 13 and the controller 14 are placed outside the air wave oscillation tube 6 and fixed. The light piston 7-1 is a porous material selected from sponge and cotton.

[0025] A monitoring method of a monitoring device for monitoring two-phase flow information in a large-carry liquid rotating gas wave oscillation tube, when using a wired transmission-receiving element, the working process is as follows:

[0026] The sensor 7, the acquisition card 4, the microprocessor 2, the mobile power supply 3 and the air wave oscillation tube 6 rotate synchronously; the pressure fluctuation in the air wave oscillation tube 6 triggers the built-in chip 7-2 of the sensor 7, and the fluctuation data is collected by the data acquisition card 4, and the collected data is stored in the microprocessor 2. The mobile power supply 3 supplies power to the sensor 7, the acquisition card 4 and the microprocessor 2;

[0027] When using wireless transmission-reception components, the working process is as follows:

[0028] The sensor 7, the wireless transmission transmitter 11, the mobile power supply 3 and the air wave oscillation tube 6 rotate synchronously; the pressure fluctuation in the air wave oscillation tube 6 triggers the built-in chip 7-2 of the sensor 7, and the fluctuation data is

[0029] The wireless transmission transmitter 11 collects and sends wireless signals, and the wireless signals are received by the receiver 12 and stored in the memory 13 .

[0030] Figure 1 The figure shows a structural schematic diagram of a wired transmission method of an experimental device for measuring the fluctuation information in a large-band liquid-gas wave oscillation tube. In the figure, this experimental device mainly includes an air intake nozzle 5, an exhaust nozzle 8, an air wave oscillation tube 6, a main shaft 9, a static balance counterweight 1, an integrated measuring element, etc., wherein the integrated measuring element is a wired transmission element, mainly including a sensor 7, a data acquisition card 4, a microprocessor 2, a mobile power supply 3, etc. All wired transmission elements are fixed on the main shaft and rotate synchronously with the air wave oscillation tube 6. The pressure fluctuation in the air wave oscillation tube 6 triggers the built-in chip 7-2 of the sensor 7, and the fluctuation data is collected by the data acquisition card 4. The collected data is stored in the microprocessor 2, and the mobile power supply 3 provides power for all measuring elements. It should be noted that the unsteady pressure fluctuation in the air wave oscillation tube 6 belongs to a high-frequency fluctuation signal, and the wired transmission method in the utility model patent ensures the stability of the data transmission process.

[0031] At the same time, this utility model patent also provides another wireless transmission method, such as Figure 2 As shown, the wireless transmission element includes a sensor 7, a transmitter 11, a receiver 12, a memory 13, a controller 14 and a mobile power source 3, etc., wherein the sensor 7, the transmitter 11, the mobile power source 3 and the air wave oscillating tube 6 rotate synchronously, and the other components are placed outside and fixed. The data provided by the sensor 7 is sent out as a wireless signal by the transmitter 11, and the wireless signal is received by the receiver 12 and stored in the memory 13. The advantage of the wireless transmission method is to reduce the rotation load and simplify the structure of the rotating parts. The disadvantage is that the wireless transmission signal is easily disturbed by the rotating magnetic field, the data transmission is distorted, and complex data processing is required later.

[0032] Figure 3 The figure shows the processing of the utility model patent for the pressure fluctuation measurement in the large liquid-carrying rotating air wave oscillation tube 6, which mainly involves filling a light piston 7-1 of negligible mass such as a sponge between the built-in chip 7-2 of the sensor 7 and the outer wall 6-1 of the air wave oscillation tube. It can form a sealed air column in front of the chip of the sensor, effectively blocking the entry of liquid and preventing the gas-liquid mixed working fluid from directly contacting the built-in chip 7-2 of the sensor, resulting in inaccurate data measurement.

[0033] Figure 4 a and b are the experimental results of the pressure fluctuation in the gas wave oscillation tube when there is no liquid barrier structure and when there is a liquid barrier structure. Figure 4 The experimental results of the outer wall of middle a show that the pressure is very chaotic and does not show a periodic fluctuation pattern; Figure 4 The measurement results in middle b show that the upper and lower walls exhibit periodic fluctuations of the same frequency.

[0034] In actual work, the centrifugal force on the outer wall 6-1 of the air wave oscillation tube is the largest, and the liquid in the tube will be concentrated on the outer wall under the action of centrifugal force. The utility model patent measures the pressure difference between the outer wall 6-1 and the inner wall 6-2 as an indicator for evaluating the distribution law of the liquid in the tube, which makes up for the lack of technical means to obtain the distribution law of the liquid in the rotating air wave oscillation tube.

[0035] Considering that the conical air wave oscillation tube 6-3 and the curved air wave oscillation tube 6-4 are helpful to improve the liquid adaptability of the air wave oscillation tube, the experimental device and experimental method of the utility model can be applied to the conical air wave oscillation tube 6-3 and the curved air wave oscillation tube 6-4, such as Figure 5 and Figure 6 As shown. Figure 6 The curved air wave oscillation tube shown in the figure adopts the structure in patent CN202110779010.X.

Claims

1. A monitoring device for two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube, wherein an air inlet nozzle and an exhaust nozzle are fixedly arranged on the main shaft seat of the device, characterized in that: The air wave oscillation tube is arranged at one end of the main shaft frame, and a static balance weight is arranged at the other end of the main shaft frame. The main shaft drives the air wave oscillation tube and the static balance weight to rotate through the main shaft frame, and the two ends of the air wave oscillation tube are matched with the air inlet nozzle and the exhaust nozzle respectively. Sensors are arranged on the outer wall surface and the inner wall surface of the air wave oscillation tube, and a light piston is arranged in the sensor connection column between the outer wall surface of the air wave oscillation tube and the sensor built-in chip; a sealing air column is arranged between the light piston and the sensor built-in chip; The device also includes a transmission-receiving element, which includes a wired transmission-receiving element or a wireless transmission-receiving element. The wired transmission-receiving element includes a data acquisition card, a microprocessor and a mobile power supply, and the wired transmission-receiving element is fixed on the main shaft; the wireless transmission-receiving element includes a wireless transmission transmitter, a wireless transmission receiver, a memory and a controller; the wireless transmission transmitter is fixed on the main shaft; the wireless transmission receiver, the memory and the controller are placed outside the air wave oscillation tube and are fixed.

2. The monitoring device for two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube according to claim 1 is characterized in that: The light piston is made of porous material and is selected from sponge or cotton.

3. The monitoring device for two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube according to claim 1 is characterized in that: The air wave oscillation tube is a straight air wave oscillation tube, a conical air wave oscillation tube or a curved air wave oscillation tube.

4. The monitoring device for two-phase flow information in a large liquid-carrying rotating gas wave oscillation tube according to claim 1 is characterized in that: The sensor is a temperature measurement sensor, a pressure measurement sensor, a liquid film thickness measurement sensor or a visual measurement sensor.

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