Method and device suitable for carbon dioxide pipeline leakage experiment test

Abstract

The invention relates to the technical field of carbon dioxide pipeline conveying, in particular to a method and device suitable for a carbon dioxide pipeline leakage experiment test. Introducing carbon dioxide gas into the device, and scavenging the device; after the test pipeline, the temperature sensor, the pressure sensor and the safety protection device are checked again, the sand is loaded into the sand box; and performing a carbon dioxide pipeline leakage experiment test on the test pipeline. The device comprises a carbon dioxide gas cylinder, a three-way valve, a constant-temperature water bath storage tank and a sand box. The test pipeline is buried in the sand box, pressure and temperature parameters of the buried multiphase carbon dioxide pipeline in the leakage process are collected, controlled and the like, different leakage morphology characteristics and leakage opening area wall temperature changes are obtained, the leakage caliber, the leakage position and the like can be rapidly and qualitatively judged after a pipeline leakage accident happens, and the leakage detection accuracy is improved. And the follow-up emergency rescue work can be conveniently carried out.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide pipeline transportation, and is a method and device suitable for carbon dioxide pipeline leakage experiment testing. BACKGROUND

[0002] Carbon dioxide exists in four states: supercritical state, liquid state, solid state and gaseous state. During the operation of long-distance carbon dioxide pipelines, accidents such as corrosion perforation and third-party damage leading to leakage will inevitably occur. Carbon dioxide will form a transient flow in the pipeline, which is prone to phase change and low-temperature conditions (-60℃). The physical properties such as density and specific heat capacity will change in steps, causing dramatic changes in operating parameters such as pressure and temperature, impacting the pipeline and equipment, causing damage and endangering pipeline safety. Carbon dioxide is a colorless, odorless and non-toxic gas, which is not flammable and not explosive. Compared with natural gas, carbon dioxide is a non-toxic suffocating gas with a higher density than air. After leakage, it is easy to gather in low-lying areas or enclosed spaces, not only damaging the surrounding environment, but also having a certain inhibitory effect on soil microbial growth. It may also cause suffocation, poisoning, frostbite and even death in humans and animals (half-lethal concentration 5%), so it is necessary to develop a carbon dioxide pipeline leakage / diffusion emergency rescue plan.

[0003] Due to the differences between carbon dioxide pipeline characteristics and methane, the natural gas pipeline emergency rescue technology cannot be directly applied. There are no long-distance carbon dioxide pipelines in China, and no operation experience to follow. The domestic design standard SH / T3202-2018 "Carbon Dioxide Pipeline Engineering Design Standard" does not cover carbon dioxide pipeline leakage / diffusion emergency rescue and other content. At present, carbon dioxide pipeline leakage research mostly assumes that the pipeline is overhead and focuses on the process of high-pressure carbon dioxide near-field multiphase jet flow and high-pressure carbon dioxide pipeline leakage far-field diffusion. There are few experimental verifications of buried carbon dioxide pipeline leakage, and no reports on buried pipeline leakage / diffusion emergency rescue measures. When the pipeline is buried underground, the interaction between carbon dioxide medium, soil and pipeline makes the medium leakage law very different from that of aboveground pipelines, involving multi-field coupling problems such as soil seepage field, temperature field and concentration field. The measurement method of part of the aboveground carbon dioxide pipeline leakage test mostly uses electric heating tape to heat the main pipeline to achieve the experimental pressure and temperature, in order to solve the problem of realizing different phases (gas phase, liquid phase, supercritical) of carbon dioxide pipeline. Electric heating tape transfers heat to the outer wall of the pipeline, and then increases the temperature of the fluid in the pipeline through heat conduction. This easily leads to uneven heating of the pipeline, resulting in inconsistent phase states of the fluid in the pipeline, which in turn affects the test results. On the other hand, electric heating tape cannot directly regulate the pressure of the fluid in the pipeline. It is through heating the fluid, causing the thermal motion of the fluid molecules to increase, and the heated expansion, so the pressure rises. Therefore, the adjustment of the test pressure in the pipeline is not controllable through the work of the electric heating tape.

[0004] The current carbon dioxide (CO2) pipe transportation technology patent applications are concentrated in the pipeline structure, operation characteristics, pipeline materials, pipeline protection, etc. The Chinese patent file with the publication number CN105699023B discloses a measuring device and measuring method suitable for carbon dioxide pipeline venting and leakage testing; the Chinese patent file with the publication number CN116906838A discloses a carbon dioxide conveying pipeline leakage early warning positioning method and device, although the patent involves releasing carbon dioxide fluid, it does not consider the influence of impurity types and contents on the changes of in-pipe pressure, temperature and phase state during the release process, does not consider the release mode of buried pipelines, and does not provide a leakage measuring device and method suitable for multi-phase carbon dioxide pipelines containing impurities.

[0005] At the same time, the Chinese patent file with the publication number CN115219106A discloses a method for dynamic measurement of compressed air pipeline network leakage based on cloud computing, which combines cloud computing technology with industrial field monitoring technology to quantitatively monitor the leakage of compressed air pipeline network; the Chinese patent file with the publication number CN104111145B discloses a combustible refrigerant simulation leakage device and leakage concentration measuring device, which is used for leakage of combustible refrigerant. However, the measuring method does not aim at the characteristics of multi-phase carbon dioxide pipelines containing impurities.

[0006] Therefore, the leakage testing of buried multi-phase carbon dioxide pipelines is a technical problem that needs to be solved. SUMMARY

[0007] The present application provides a method and device suitable for carbon dioxide pipeline leakage experimental testing, which overcomes the shortcomings of the above-mentioned prior art, and effectively solves the problems of difficult prevention of carbon dioxide pipeline leakage and difficult emergency rescue work during leakage of buried multi-phase carbon dioxide pipelines during the existing carbon dioxide pipeline transportation process.

[0008] One of the technical solutions of the present application is achieved by the following measures: a method suitable for carbon dioxide pipeline leakage experimental testing, comprising: Firstly, perform experimental integrity inspection and device airtightness inspection; Secondly, pass carbon dioxide gas into the device to perform device gas sweeping; Thirdly, after re-inspecting the test pipeline, temperature sensor, pressure sensor and safety protection device, fill sand into the sand box; Fourthly, perform carbon dioxide pipeline leakage experimental testing on the test pipeline.

[0009] The following is a further optimization or / and improvement of the above-mentioned one of the technical solutions: The carbon dioxide pipeline leakage experiment test on the test pipeline in the fourth step includes a buried supercritical carbon dioxide pipeline leakage experiment test, a buried dense-phase carbon dioxide pipeline leakage experiment test, a buried liquid carbon dioxide pipeline leakage experiment test, and a buried gaseous carbon dioxide pipeline leakage experiment test.

[0010] The buried supercritical carbon dioxide pipeline leakage experiment test is performed according to the following steps: Step S11, carbon dioxide liquefaction: the gas supply pressure in the carbon dioxide cylinder is adjusted to 4.5-5.0 MPa, and the temperature is 20℃, the water cooler is pre-cooled until the water temperature in the water cooler is 4℃, and then the liquefaction of carbon dioxide is performed; Step S12, experimental temperature regulation: the constant-temperature water bath storage tank and the constant-temperature water bath connected with the pipeline are started, and the temperature of the constant-temperature water bath is 40℃; Step S13, fluid filling and pressurization: when the volume of the liquid carbon dioxide in the water cooler set is half of the volume of the water cooler set, the fluid filling and pressurization of the constant-temperature water bath storage tank and the connected pipeline are performed, until the state of the carbon dioxide in the constant-temperature water bath storage tank and the connected pipeline reaches the supercritical state required by the experiment, and the volume of the carbon dioxide in the constant-temperature water bath storage tank reaches two-thirds of the volume of the constant-temperature water bath storage tank, the fluid filling and pressurization is ended; Step S14, pipeline leakage test: the liquid carbon dioxide enters the test pipeline, and when the pressure in the pipeline is higher than the burst pressure of 10 MPa, instantaneous leakage is realized.

[0011] The buried dense-phase carbon dioxide pipeline leakage experiment test is performed according to the following steps: Step S21, carbon dioxide liquefaction: the gas supply pressure in the carbon dioxide cylinder is adjusted to 4.5-5.0 MPa, and the temperature is 20℃, the water cooler is pre-cooled until the water temperature in the water cooler is 4℃, and then the liquefaction of carbon dioxide is performed; Step S22, experimental temperature regulation: the constant-temperature water bath storage tank and the constant-temperature water bath connected with the pipeline are started, and the temperature of the constant-temperature water bath is 20℃; Step S23, fluid filling and pressurization: when the volume of the liquid carbon dioxide in the water cooler set is half of the volume of the water cooler set, the fluid filling and pressurization of the constant-temperature water bath storage tank and the connected pipeline are performed, until the state of the carbon dioxide in the constant-temperature water bath storage tank and the connected pipeline reaches the dense-phase state required by the experiment, and the volume of the carbon dioxide in the constant-temperature water bath storage tank reaches two-thirds of the volume of the constant-temperature water bath storage tank, the fluid filling and pressurization is ended; Step S24, pipeline leakage test: the liquid carbon dioxide enters the test pipeline, and when the pressure in the pipeline is higher than the burst pressure of 10 MPa, instantaneous leakage is realized.

[0012] The buried liquid carbon dioxide pipeline leakage experiment test is performed according to the following steps: Step S31, carbon dioxide liquefaction: the carbon dioxide gas cylinder is adjusted to 4.5-5.0 MPa, the temperature is 20 DEG C, the water cooling machine is pre-cooled to 0 DEG C, and the carbon dioxide is liquefied; Step S32, experimental temperature regulation: the constant temperature water bath storage tank and the constant temperature water bath connected pipeline are started, and the constant temperature water bath temperature is 0 DEG C; Step S33, fluid filling and pressurization: when the liquid carbon dioxide volume in the water cooling unit is half of the water cooling unit volume, the constant temperature water bath storage tank and the connected pipeline are fluid filled and pressurized, the carbon dioxide state in the constant temperature water bath storage tank and the connected pipeline reaches the supercritical state required by the experiment, and when the carbon dioxide volume in the constant temperature water bath storage tank reaches two-thirds of the constant temperature water bath storage tank volume, the fluid filling and pressurization is ended; Step S34, pipeline leakage test: liquid carbon dioxide enters the test pipeline, and when the pressure in the pipeline is higher than the burst pressure of 4 MPa, instantaneous leakage is realized.

[0013] The above-mentioned buried gaseous carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S41, experimental temperature regulation: the constant temperature water bath storage tank and the constant temperature water bath connected pipeline are started, and the constant temperature water bath temperature is 30 DEG C; Step S42, gas filling and pressurization: the carbon dioxide gas cylinder is adjusted to 4.5-5.0 MPa, the temperature is 20 DEG C, the constant temperature water bath storage tank and the connected pipeline are gas filled and pressurized, the carbon dioxide state in the constant temperature water bath storage tank and the connected pipeline reaches the gas state required by the experiment, and when the carbon dioxide volume in the constant temperature water bath storage tank reaches two-thirds of the constant temperature water bath storage tank volume, the gas filling and pressurization is ended; Step S43, pipeline leakage test: liquid carbon dioxide enters the test pipeline, and when the pressure in the pipeline is higher than the burst pressure of 4 MPa, instantaneous leakage is realized.

[0014] The technical scheme two of the application is realized by the following measures: a device for implementing a method suitable for carbon dioxide pipeline leakage experiment test, comprising a carbon dioxide gas cylinder, a three-way valve, a constant temperature water bath storage tank and a sand box, a gas cylinder outlet pipeline is fixedly communicated between the top outlet of the carbon dioxide gas cylinder and the upper port of the three-way valve, a liquid carbon dioxide generation pipeline is fixedly communicated between the right port of the three-way valve and the inlet of the constant temperature water bath storage tank, a gaseous carbon dioxide pipeline is fixedly communicated between the lower port of the three-way valve and the liquid carbon dioxide generation pipeline, a connecting pipeline is fixedly communicated between the outlet of the constant temperature water bath storage tank and the inlet of the sand box, a test pipeline is arranged in the sand box, and the outlet of the connecting pipeline is fixedly communicated with the inlet of the test pipeline.

[0015] The following is a further optimization or / and improvement of the above-mentioned technical scheme two: The water cooling machine and the liquid plunger pump are fixedly installed on the liquid carbon dioxide generating pipeline, a first electric ball valve, a first pressure sensor and a first temperature sensor are fixedly installed on the liquid carbon dioxide generating pipeline between the right port of the three-way valve and the water cooling machine along the medium flow direction, a second pressure sensor, a second temperature sensor, a second vortex flowmeter and a second electric ball valve are fixedly installed on the liquid carbon dioxide generating pipeline between the liquid plunger pump and the gas carbon dioxide pipeline along the medium flow direction, a third electric ball valve is fixedly installed on the gas carbon dioxide pipeline, a pneumatic ball valve is fixedly installed on the connecting pipeline, a flow regulating valve and a first vortex flowmeter are fixedly installed on the gas cylinder outlet pipeline along the medium flow direction, and a third pressure sensor and a third temperature sensor are arranged on the top of the constant-temperature water bath storage tank.

[0016] A temperature sensor group, a safety protection device, a fourth pressure sensor and a fourth temperature sensor are fixedly installed on the test pipeline along the medium flow direction, and a blind plate is arranged at the outlet of the test pipeline, wherein the safety protection device comprises a leakage hole and a bursting disc, the leakage hole is arranged on the test pipeline between the temperature sensor group and the fourth pressure sensor, and the bursting disc is fixedly installed on the leakage hole.

[0017] The controller is further included, and the constant-temperature water bath storage tank, the flow regulating valve, the first vortex flowmeter, the liquid plunger pump, the first electric ball valve, the first pressure sensor, the first temperature sensor, the second pressure sensor, the second temperature sensor, the second vortex flowmeter, the second electric ball valve, the third electric ball valve, the pneumatic ball valve, the temperature sensor group, the third pressure sensor, the third temperature sensor, the fourth pressure sensor and the fourth temperature sensor are electrically connected with the controller.

[0018] The test pipeline is buried in the sand box, so that the pressure and temperature parameters of the buried multi-phase carbon dioxide pipeline in the leakage process are collected and controlled, different leakage features and the wall temperature change of the leakage port area are obtained, the leakage diameter and the leakage position are quickly qualitatively judged after the pipeline leakage accident occurs, and the subsequent emergency rescue work is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0019] ATTACHED Figure 1 It is a front view and half sectional view structural schematic diagram of the application.

[0020] The codes in the accompanying drawings are: 1 is a carbon dioxide cylinder, 2 is a flow regulating valve, 3 is a first vortex flowmeter, 4 is a cylinder outlet pipe, 5 is a liquid carbon dioxide generation pipe, 6 is a gas carbon dioxide pipe, 7 is a first electric ball valve, 8 is a first pressure sensor, 9 is a water cooler, 10 is a liquid plunger pump, 11 is a second pressure sensor, 12 is a second vortex flowmeter, 13 is a second electric ball valve, 14 is a third electric ball valve, 15 is a constant temperature water bath tank, 16 is a third pressure sensor, 17 is a connecting pipe, 18 is a pneumatic ball valve, 19 is a test pipe, 20 is a temperature sensor group, 21 is a safety protection device, 22 is a fourth pressure sensor, 23 is a blind plate, 24 is a sand box, 25 is a first temperature sensor, 26 is a second temperature sensor, 27 is a third temperature sensor, 28 is a fourth temperature sensor, and 29 is a three-way valve. DETAILED DESCRIPTION

[0021] The present invention is not limited to the following embodiments, and specific implementation methods can be determined based on the technical solutions of the present invention and actual conditions.

[0022] The present invention will be further described below in conjunction with the embodiments: Example 1: As shown in the attached Figure 1 As shown, the test method for carbon dioxide pipeline leakage experiment includes: The first step is to conduct an experimental integrity check and a device airtightness check; The second step is to introduce carbon dioxide gas into the device to purge the device; In the third step, after rechecking the test pipe 19, temperature sensor, pressure sensor and safety protection device 21, the sand is loaded into the sand box 24; The fourth step is to conduct a carbon dioxide pipeline leakage test on the test pipeline 19.

[0023] In this invention, the experimental integrity check includes equipment integrity and experimental safety. Check that all equipment is properly connected and installed, that the pneumatic ball valve 18 is functioning properly, that the blind plate 23 of the test pipe 19 is sealed, and that the data recording system is operating normally. Check that there are no people or objects in the direction of the experimental discharge to ensure that no one enters the danger zone during the experiment.

[0024] The air tightness check includes checking the air tightness of the entire experimental pipeline before the experiment begins, filling the experimental pipeline with air at a certain pressure (4MPa to 5MPa), closing all valves, and letting it stand for more than 2 hours. If the pressure in the experimental pipeline remains stable, the experimental system is airtight and meets the experimental requirements; otherwise, the entire experimental pipeline needs to be tested for air tightness to find the leak point, reseal it, and continue to test the air tightness until it is ensured that the experimental system is airtight.

[0025] In the scavenging process, high-purity carbon dioxide gas is directly introduced into the constant-temperature water bath storage tank 15, the connecting pipeline 17 and the test pipeline 19, and the air is exhausted by using the characteristic that the carbon dioxide gas is heavier than the air, so as to ensure that there is no impurity gas in the constant-temperature water bath storage tank 15, the connecting pipeline 17 and the test pipeline 19.

[0026] After it is ensured that the fourth temperature sensor 28, the fourth pressure sensor 22 and the bursting disc installed on the test pipeline 19 are intact, the sand is filled into the sand box 24 by means of an excavator or manually.

[0027] Embodiment 2: As an optimization of the above-mentioned embodiments, as shown in the accompanying drawings Figure 1 In the fourth step, the carbon dioxide pipeline leakage experiment test on the test pipeline 19 includes a buried supercritical state carbon dioxide pipeline leakage experiment test, a buried dense phase carbon dioxide pipeline leakage experiment test, a buried liquid carbon dioxide pipeline leakage experiment test and a buried gaseous carbon dioxide pipeline leakage experiment test.

[0028] Many scholars at home and abroad have conducted many studies on the phase diagram of carbon dioxide (CO2). The phase diagram of CO2 has two obvious characteristic points: a triple point (-56℃, 0.52MPa) and a critical point (31℃, 7.38MPa). The phase state of CO2 can be divided into five regions: a supercritical region, a dense phase region, a liquid phase region, a solid phase region and a gaseous phase region. When the pressure and the temperature are both above the critical pressure and the critical temperature, CO2 presents a supercritical state.

[0029] The density of CO2 changes most dramatically near the critical temperature (about 30℃), that is, near the critical temperature point, a slight change in temperature leads to a relatively sharp change in density, but with the increase of pressure, the sharpness of the change in density is reduced. Regarding the change of the density of CO2 with the pressure and the temperature, at the same temperature, the density of CO2 continuously decreases with the decrease of the pressure; at the same pressure, the density continuously increases with the decrease of the temperature. When changing from the dense phase region to the liquid phase region, the density of CO2 changes slowly; when changing from the liquid phase region to the gaseous phase region, the density of CO2 changes in a stepwise manner, from 600kg / m 3 to 1200kg / m 3 to 1kg / m 3 to 200kg / m 3 The sharp fluctuation of the density causes the volume of the CO2 fluid in the pipeline to change in a fluctuating manner, and under the constraint of the fixed volume of the pipeline, the sharply fluctuating CO2 fluid will produce a sharp pulsating impact on the pipeline, which endangers the safety of the pipeline.

[0030] In order to prepare CO2 that meets the experimental pressure and temperature conditions, the preparation method of supercritical phase state CO2 is taken as an example in the present application to describe the required phase state CO2, and the specific method is as follows: First, according to the end state of supercritical CO2 pressure and temperature, the CO2 fluid density can be determined; according to the fixed volume of the pipeline, the mass of CO2 required to fill the pipeline can be calculated, and the mass of CO2 required to fill the constant temperature water bath storage tank 15 is half of the mass of the connecting pipeline 17, that is, the total CO2 mass required for the experiment can be obtained; Second, knowing the required CO2 mass obtained in the first step, according to the monitoring flow of the first vortex flow meter 3 at the outlet of the carbon dioxide cylinder 1, the working time of the carbon dioxide cylinder 1 opening valve can be calculated to achieve the CO2 mass supplied by the carbon dioxide cylinder 1 to reach the required CO2 mass for the experiment; Third, the CO2 gas supplied by the carbon dioxide cylinder 1 is cooled and liquefied by the water chiller 9 to realize the transition of CO2 from gas phase to liquid phase; the liquid CO2 in the steel cylinder of the water chiller 9 is pumped into the constant temperature water bath storage tank 15 by the liquid piston pump 10; Fourth, the liquid CO2 is heated by the water bath of the constant temperature water bath storage tank 15, part of the liquid phase CO2 is gasified, and the CO2 is converted from a single liquid phase to a gas-liquid mixture, and the gas phase CO2 and liquid phase CO2 in the constant temperature water bath storage tank 15 are self-balanced; Fifth, the water bath continues to heat the CO2 gas-liquid mixture in the constant temperature water bath storage tank 15, and the CO2 pressure rises with the rise of the temperature, and the CO2 fluid phase state first moves along the CO2 gas-liquid equilibrium line, and then enters the liquid phase, the dense phase and the supercritical phase in turn (the phase transition path is gas-liquid mixture-liquid phase-dense phase-supercritical phase).

[0031] Specifically: assuming that the supercritical phase CO2 pressure required for the experiment is 12.0MPa and the temperature is 40℃, the density is calculated as 717kg / m 3 The volume of the connecting pipeline 17 is 2m 3 The mass of CO2 required to fill the connecting pipeline 17 is calculated as 1434kg, and the mass of CO2 required to fill the constant temperature water bath storage tank 15 is half of the mass of the connecting pipeline 17, that is, the total CO2 mass required for the experiment is 2868kg.

[0032] The liquefaction temperature of the water chiller 9 is regulated to 4℃ to realize the transition of CO2 from gas phase to liquid phase; the liquid phase CO2 in the steel cylinder of the water chiller 9 is pumped into the constant temperature water bath storage tank 15 by the liquid piston pump 10; the liquid phase CO2 is heated by the water bath of the constant temperature water bath storage tank 15, part of the liquid is gasified, and if the temperature of the gas-liquid mixture is 4℃, the pressure of the gas-liquid mixture will be stabilized at about 3.8MPa; continue to heat the gas-liquid mixture, the CO2 pressure rises with the rise of the temperature, and the early carbon dioxide phase changes along the gas-liquid equilibrium line (the gas-liquid ratio gradually decreases), and the gas-liquid mixture density maintains 717kg / m 3When the CO2 temperature reaches 24°C, the pressure is about 6.3MPa, and then it enters the liquid phase region; when the CO2 temperature reaches 27.4°C, the pressure is about 7.38MPa, and then it enters the dense phase region; when the CO2 temperature reaches 31.1°C, the pressure is about 8.7MPa, and then it enters the supercritical phase region; when the temperature is continued to be heated to 40°C, the pressure can reach 12MPa, and the preparation of supercritical phase CO2 is completed.

[0033] In the present invention, as required, the temperature and pressure ranges under the experimental operating conditions of each phase of carbon dioxide are as follows: Gaseous state: pressure 4.5MPa to 5.0MPa, temperature 22℃ to 40℃; Liquid: pressure 4.5MPa to 5.0MPa, temperature -20℃ to 5℃.

[0034] Dense phase: pressure 8.5MPa to 14MPa, temperature -20℃ to 20℃.

[0035] Supercritical state: pressure 8.5MPa to 14MPa, temperature 35℃ to 40℃.

[0036] The gas supply pressure of carbon dioxide cylinder 1 is 4.5MPa to 5.0MPa, and the gas supply temperature is 20℃.

[0037] Example 3: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, the buried supercritical carbon dioxide pipeline leakage test is carried out according to the following steps: Step S11, CO2 liquefaction: The gas supply pressure in the CO2 cylinder 1 is adjusted to 4.5 MPa to 5.0 MPa and the temperature is 20°C. The CO2 liquefaction water chiller 9 is started for pre-cooling. When the water temperature in the chiller drops to 4°C, the flow control valve 2 of the CO2 cylinder 1 and the first electric ball valve 7 at the inlet of the liquefaction water chiller 9 are opened to liquefy the CO2. Step S12, experimental temperature control: start the constant temperature water bath tank 15 and the constant temperature water bath connected to the pipe 17, wherein the constant temperature water bath temperature is 40°C; Step S13, fluid filling and pressurization: When the volume of liquid carbon dioxide in the water-cooling machine 9 group reaches half of the volume of the water-cooling machine 9 group, the constant temperature water bath storage tank 15 and the connecting pipe 17 are filled with fluid and pressurized. The temperature and pressure in the constant temperature water bath storage tank 15 and the connecting pipe 17 need to be closely monitored during the entire pressurization process. When the carbon dioxide state in the constant temperature water bath storage tank 15 and the connecting pipe 17 reaches the supercritical state (14 MPa, 40°C) required for the experiment, and the carbon dioxide volume in the constant temperature water bath storage tank 15 reaches two-thirds of the volume of the constant temperature water bath storage tank 15, the supercritical carbon dioxide preparation is completed, and the flow regulating valve 2, the water-cooling machine 9, the liquid plunger pump 10, and the first electric ball valve 7 are closed, and the fluid filling and pressurization are terminated; Step S14, pipeline leakage test: ensure that all data collection is opened, open the pneumatic ball valve 18, liquid carbon dioxide into the test pipeline 19, when the pressure in the pipe is higher than 10 MPa burst pressure, realize the instantaneous leakage. All personnel in the leakage area evacuate.

[0038] After the leakage stops, all data collection devices are closed, and after the carbon dioxide concentration in the leakage area decreases, the sand box 24 is disassembled, the sand on the pipeline is removed, and the frozen soil ball and dry ice layer are measured and photographed. After the sand box 24 is disassembled, the test site is cleaned and prepared for the next test.

[0039] Example 4: As an optimization of the above examples, as shown in the accompanying Figure 1 The buried dense-phase carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S21, carbon dioxide liquefaction: adjust the gas supply pressure in the carbon dioxide cylinder 1 to 4.5-5.0 MPa and the temperature to 20°C, start the carbon dioxide liquefaction water cooler 9 group for precooling, open the flow regulating valve 2 of the carbon dioxide cylinder 1 and the first electric ball valve 7 at the inlet of the liquefaction water cooler 9 group when the water temperature in the group decreases to 4°C, and carry out carbon dioxide liquefaction; Step S22, experimental temperature regulation: start the constant-temperature water bath storage tank 15 and the constant-temperature water bath connected by the pipeline 17, wherein the constant-temperature water bath temperature is 20°C; Step S23, fluid filling and pressurization: when the volume of the liquid carbon dioxide in the water cooler 9 group is half of the volume of the water cooler 9 group, fluid filling and pressurization are carried out on the constant-temperature water bath storage tank 15 and the connecting pipeline 17, until the carbon dioxide in the constant-temperature water bath storage tank 15 and the connecting pipeline 17 reaches the required dense-phase state (14 MPa, 20°C) and the volume of the carbon dioxide in the constant-temperature water bath storage tank 15 reaches two-thirds of the volume of the constant-temperature water bath storage tank 15, which indicates that the preparation of the dense-phase carbon dioxide is completed, and the flow regulating valve 2, the water cooler 9, the liquid piston pump 10, and the first electric ball valve 7 are closed, ending the fluid filling and pressurization; Step S24, pipeline leakage test: ensure that all data collection is opened, open the pneumatic ball valve 18, liquid carbon dioxide into the test pipeline 19, when the pressure in the pipe is higher than 10 MPa burst pressure, realize the instantaneous leakage. All personnel in the leakage area evacuate.

[0040] After the leakage stops, all data collection devices are closed, and after the carbon dioxide concentration in the leakage area decreases, the sand box 24 is disassembled, the sand on the pipeline is removed, and the frozen soil ball and dry ice layer are measured and photographed. After the sand box 24 is disassembled, the test site is cleaned and prepared for the next test.

[0041] Example 5: As an optimization of the above examples, as shown in the accompanying Figure 1As shown, the buried liquid carbon dioxide pipeline leakage experiment test is performed according to the following steps: Step S31, carbon dioxide liquefaction: the gas supply pressure in the carbon dioxide cylinder 1 is adjusted to 4.5-5.0 MPa, and the temperature is 20°C. The carbon dioxide liquefaction water cooler 9 group is started for precooling. When the water temperature in the group is reduced to 0°C, the flow regulating valve 2 of the carbon dioxide cylinder 1 and the first electric ball valve 7 at the inlet of the liquefaction water cooler 9 group are opened, and the liquefaction of carbon dioxide is performed. Step S32, experimental temperature regulation: the constant temperature water bath tank 15 and the constant temperature water bath connected pipeline 17 are started, wherein the constant temperature water bath temperature is 0°C. Step S33, fluid filling and pressurization: when the volume of liquid carbon dioxide in the water cooler 9 group is half of the volume of the water cooler 9 group, the fluid filling and pressurization of the constant temperature water bath tank 15 and the connected pipeline 17 are performed. When the state of carbon dioxide in the constant temperature water bath tank 15 and the connected pipeline 17 reaches the supercritical state (4 MPa, 0°C) required by the experiment, and the volume of carbon dioxide in the constant temperature water bath tank 15 reaches two-thirds of the volume of the constant temperature water bath tank 15, the preparation of liquid carbon dioxide is completed, and the flow regulating valve 2, the water cooler 9, the liquid piston pump 10, and the first electric ball valve 7 are closed, and the fluid filling and pressurization is ended. Step S34, pipeline leakage test: liquid carbon dioxide enters the test pipeline 19. When the pressure in the pipeline is higher than the burst pressure of 4 MPa, instantaneous leakage is achieved. All personnel in the leakage area are evacuated.

[0042] After the leakage stops, all data acquisition equipment is closed, and after the carbon dioxide concentration in the leakage area decreases, the sand box 24 is disassembled, the sand on the pipeline is removed, and the frozen soil ball and dry ice layer are measured and photographed. After the sand box 24 is disassembled, the test site is cleaned, and preparation is made for the next test.

[0043] Example 6: As an optimization of the above examples, as shown in the attached Figure 1 As shown, the buried liquid carbon dioxide pipeline leakage experiment test is performed according to the following steps: Step S41, experimental temperature regulation: the constant temperature water bath tank 15 and the constant temperature water bath connected pipeline 17 are started, wherein the constant temperature water bath temperature is 30°C. Step S42, gas filling and pressurization: the gas supply pressure in the carbon dioxide cylinder 1 is adjusted to 4.5-5.0 MPa, and the temperature is 20°C. The constant temperature water bath storage tank 15 and the connecting pipeline 17 are gas-filled and pressurized until the carbon dioxide in the constant temperature water bath storage tank 15 and the connecting pipeline 17 reaches the required gas state (4 MPa, 30°C) and the volume of carbon dioxide in the constant temperature water bath storage tank 15 reaches two-thirds of the volume of the constant temperature water bath storage tank 15, indicating that the gaseous carbon dioxide preparation is complete. The flow regulating valve 2, the water chiller 9, the liquid piston pump 10, and the first electric ball valve 7 are closed, and the gas filling and pressurization is completed. Step S43, pipeline leakage test: liquid carbon dioxide enters the test pipeline 19, and when the pressure in the pipeline is higher than the burst pressure of 4 MPa, instantaneous leakage is achieved.

[0044] Example 7: As shown in the accompanying Figure 1 The device for testing the carbon dioxide pipeline leakage experiment method includes a carbon dioxide cylinder 1, a three-way valve 29, a constant temperature water bath storage tank 15, and a sand box 24. The carbon dioxide cylinder 1 is fixedly connected to the three-way valve 29 through the cylinder outlet pipeline 4. The three-way valve 29 is fixedly connected to the constant temperature water bath storage tank 15 through the liquid carbon dioxide generation pipeline 5. The three-way valve 29 is fixedly connected to the liquid carbon dioxide generation pipeline 5 through the gaseous carbon dioxide pipeline 6. The constant temperature water bath storage tank 15 is fixedly connected to the sand box 24 through the connecting pipeline 17. The sand box 24 is provided with a test pipeline 19. The connecting pipeline 17 is fixedly connected to the test pipeline 19.

[0045] Example 8: As an optimization of the above-mentioned examples, as shown in the accompanying Figure 1 The liquid carbon dioxide generation pipeline 5 is fixedly provided with a water chiller 9 and a liquid piston pump 10. The liquid carbon dioxide generation pipeline 5 between the three-way valve 29 and the water chiller 9 is fixedly provided with a first electric ball valve 7, a first pressure sensor 8, and a first temperature sensor 25 in sequence along the medium flow direction. The liquid carbon dioxide generation pipeline 5 between the liquid piston pump 10 and the gaseous carbon dioxide pipeline 6 is fixedly provided with a second pressure sensor 11, a second temperature sensor 26, a second vortex flow meter 12, and a second electric ball valve 13 in sequence along the medium flow direction. The gaseous carbon dioxide pipeline 6 is fixedly provided with a third electric ball valve 14. The connecting pipeline 17 is fixedly provided with a pneumatic ball valve 18. The cylinder outlet pipeline 4 is fixedly provided with a flow regulating valve 2 and a first vortex flow meter 3 in sequence along the medium flow direction. The constant temperature water bath storage tank 15 is provided with a third pressure sensor 16 and a third temperature sensor 27.

[0046] According to the need, the constant temperature water bath storage tank 15 is used as a carbon dioxide storage container in the buried pipeline leakage test in the application, which not only ensures that the carbon dioxide has a stable phase state during discharge, but also ensures that there is enough carbon dioxide discharge amount, which is more close to the working condition of the small hole leakage of the industrial carbon dioxide pipeline.

[0047] In the application, the volume of a single carbon dioxide cylinder 1 can be 40L, which can reach 4.5MPa to 5.0MPa at room temperature, and the filling mass of carbon dioxide is 18kg. The experiment can also be supplied with gas by a cylinder group composed of multiple carbon dioxide cylinders 1 connected in parallel. By adjusting the opening degree of the flow regulating valve 2 at the outlet of the carbon dioxide cylinder 1, the gas supply demand can be easily realized. The water cooler 9 is at least one, and can also be a water cooler unit composed of multiple water coolers 9. In addition to the gaseous carbon dioxide pipeline discharge experiment, the gas in the carbon dioxide cylinder 1 first enters the water cooler unit through the liquid carbon dioxide generating pipeline 5, and the temperature is maintained at 4℃ through the refrigeration of the water cooler unit, so as to ensure that the carbon dioxide is always in a liquid state.

[0048] Through the pressurization of the liquid piston pump 10, the liquid carbon dioxide in the water cooler unit is pumped into the constant temperature water bath storage tank 15, so that the pressure of the carbon dioxide in the constant temperature water bath storage tank 15 can be increased to more than 8MPa, that is, above the critical pressure. At the same time, the circulating water bath system can realize stable adjustment of the test temperature condition of the carbon dioxide storage tank. The temperature control range of the constant temperature water bath is 5℃ to 60℃, and the temperature control accuracy is ±0.1℃.

[0049] According to the need, the carbon dioxide storage tank can also be provided with a liquid level meter. The liquid level amount of the injected gas-liquid can be known by observing the liquid level meter value.

[0050] In the embodiment 9, as an optimization of the above-mentioned embodiments, the temperature sensor group 20, the safety protection device 21, the fourth pressure sensor 22 and the fourth temperature sensor 28 are fixedly installed on the test pipeline 19 in sequence along the medium flow direction. The test pipeline 19 is provided with a blind plate 23 at the outlet. The safety protection device 21 includes a leakage hole and a bursting disc. The leakage hole is arranged on the test pipeline 19 between the temperature sensor group 20 and the fourth pressure sensor 22, and the bursting disc is fixedly installed on the leakage hole.

[0051] According to the need, the test pipeline 19 is arranged with a rapid response temperature sensor group 20 (thermocouple temperature sensor) to collect the temperature field change of the outer wall surface of the pipeline, the temperature sensor group 20 (8 temperature sensors) is arranged on one side of the leakage port, and the thermocouples arranged at a position close to the leakage port of the test pipeline 19 should be as dense as possible, and the farther the distance is, the larger the interval is. In order to obtain the phase change law of the region near the leakage port of the test pipeline 19, a fourth pressure sensor 22 and a fourth temperature sensor 28 are arranged at a position downstream of the leakage port, and the seals between the fourth pressure sensor 22 and the fourth temperature sensor 28 and the test pipeline 19 are all hard seals.

[0052] In the embodiment 10, as an optimization of the above-mentioned embodiments, the device further comprises a controller, and the constant-temperature water bath storage tank 15, the flow regulating valve 2, the first vortex flowmeter 3, the liquid piston pump 10, the first electric ball valve 7, the first pressure sensor 8, the first temperature sensor 25, the second pressure sensor 11, the second temperature sensor 26, the second vortex flowmeter 12, the second electric ball valve 13, the third electric ball valve 14, the pneumatic ball valve 18, the temperature sensor group 20, the third pressure sensor 16, the third temperature sensor 27, the fourth pressure sensor 22 and the fourth temperature sensor 28 are all electrically connected with the controller.

[0053] According to the need, in addition to being provided with a safety valve, a temperature sensor and a pressure sensor, the constant-temperature water bath storage tank 15 in the application is also provided with a base, and a safety valve with a take-off pressure of 16 MPa is used to ensure that the pressure in the storage tank does not exceed the pressure. The constant-temperature water bath storage tank 15 is built on the base, the gravity center of the device is lowered through the base steel block, and the function of preventing damage caused by the reaction force is also achieved.

[0054] According to the need, the controller in the application can be an ARM720T microprocessor, and the data signals of the pressure sensor, the temperature sensor, the electric ball valve and the vortex flowmeter are collected and comprehensively processed to realize automatic control of the device.

[0055] In the application, the connecting pipeline and the constant-temperature water bath storage tank 15 share one water bath system, the connecting pipeline is connected to the bottom of the constant-temperature water bath storage tank 15, the end of the connecting pipeline is connected with the pneumatic ball valve 18, and the pneumatic ball valve 18 is used to control the start and stop of the release experiment. The pneumatic execution time can be controlled to be about 0.5 s, which meets the requirements of the test conditions. The pneumatic ball valve 18 used in the test is a pneumatic ball valve 18, which is composed of a ball valve and a pneumatic actuator. The pneumatic actuator converts the gas pressure into thrust to push the valve stem to rotate. Because the temperature of the carbon dioxide medium is very low during the test, it will cause the sealing failure of the ordinary ball valve, therefore, a low-temperature ball valve is selected, the valve core material is 304 stainless steel, and the design pressure is 10 MPa, which can meet the low-temperature sealing requirement.

[0056] The pneumatic ball valve 18 is connected with a test pipeline 19 at the end, and the test pipeline 19 is provided with a leakage hole. The leakage hole is provided with a rupture disc, and the rupture disc is selected as a flat type with a groove. When the pressure in the pipeline is higher than the burst pressure, instantaneous leakage is realized. The end of the test pipeline 19 is sealed by a blind plate 23.

[0057] The test pipeline 19 is arranged in the middle of a sand box 24 on the ground, and the sand box 24 is filled with sand as a buried medium. The test pipeline 19 is buried in the soil at a certain depth through the sand box 24. The leakage hole is located in the central position of the sand box 24. The frame of the sand box 24 is welded by angle steel, and the surface structure is detachable except the surface where the test pipeline 19 enters. During the test preparation, the surface structure is detached. After the test pipeline 19 is fixed, the detachable surface structure is installed, and the soil is filled into the sand box 24. After the test is completed, the surface structure is detached, the soil is cleaned, the leakage hole around the test pipeline 19 is photographed, and the size of the frozen soil ball is measured.

[0058] In the present application, the devices and apparatuses used are the devices and apparatuses commonly known in the art, unless otherwise specified.

[0059] According to the needs, the device can be provided with conventional valves, thermometers and pressure gauges commonly known in the art on the pipelines and equipment of the device for testing the leakage test method of the carbon dioxide pipeline.

[0060] As described above, the test pipeline is buried in the sand box, the pressure and temperature parameters in the leakage process of the buried multi-phase carbon dioxide pipeline are collected and controlled, different leakage features and the wall temperature change in the leakage hole area are obtained, which is helpful for quickly determining the leakage diameter and leakage position after the pipeline leakage accident occurs, and facilitates the subsequent emergency rescue work.

[0061] The above technical features constitute the embodiments of the present application, which have strong adaptability and implementation effect. The unnecessary technical features can be added or reduced according to the actual needs to meet the needs of different situations.

Claims

1. A method for testing carbon dioxide pipeline leakage, characterized in that The method comprises the following steps: First, carry out experimental integrity check and device airtightness check; Second, introduce carbon dioxide gas into the device, and carry out device purging; Third, after rechecking the test pipeline, temperature sensor, pressure sensor and safety protection device, fill the sand into the sand box; Fourth, carry out carbon dioxide pipeline leakage experiment test on the test pipeline.

2. The method for testing the leakage of a carbon dioxide pipeline according to claim 1, wherein In the fourth step, the carbon dioxide pipeline leakage experiment test on the test pipeline comprises buried supercritical state carbon dioxide pipeline leakage experiment test, buried dense phase carbon dioxide pipeline leakage experiment test, buried liquid carbon dioxide pipeline leakage experiment test and buried gaseous carbon dioxide pipeline leakage experiment test.

3. The method for testing the leakage of a carbon dioxide pipeline according to claim 2, wherein The buried supercritical state carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S11, carbon dioxide liquefaction: adjust the gas supply pressure in the carbon dioxide cylinder to 4.5-5.0 MPa and the temperature to 20℃, and precool the water cooler to 4℃, and then carry out carbon dioxide liquefaction; Step S12, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 40℃; Step S13, fluid filling and pressurization: when the volume of liquid carbon dioxide in the water cooler set reaches half of the volume of the water cooler set, carry out fluid filling and pressurization on the constant temperature water bath storage tank and the connected pipeline, until the state of carbon dioxide in the constant temperature water bath storage tank and the connected pipeline reaches the supercritical state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, and then end the fluid filling and pressurization; Step S14, pipeline leakage test: when the pressure in the pipeline is higher than the burst pressure of 10 MPa, realize instantaneous leakage.

4. The method for testing the leakage of a carbon dioxide pipeline according to claim 2 or 3, wherein The buried dense phase carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S21, carbon dioxide liquefaction: adjust the gas supply pressure in the carbon dioxide cylinder to 4.5-5.0 MPa and the temperature to 20℃, and precool the water cooler to 4℃, and then carry out carbon dioxide liquefaction; Step S22, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 20℃; Step S23, fluid filling and pressurization: when the volume of liquid carbon dioxide in the water cooler set reaches half of the volume of the water cooler set, carry out fluid filling and pressurization on the constant temperature water bath storage tank and the connected pipeline, until the state of carbon dioxide in the constant temperature water bath storage tank and the connected pipeline reaches the dense phase state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, and then end the fluid filling and pressurization; Step S24, pipeline leakage test: when the pressure in the pipeline is higher than the burst pressure of 10 MPa, realize instantaneous leakage.

5. The method for testing the leakage of carbon dioxide pipeline according to claim 2 or 3 or 4, characterized in that The buried liquid carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S31, carbon dioxide liquefaction: adjust the gas supply pressure in the carbon dioxide cylinder to 4.5-5.0 MPa and the temperature to 20℃, and precool the water cooler to 0℃, and then carry out carbon dioxide liquefaction; Step S32, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 20℃; Step S33, fluid filling and pressurization: when the volume of liquid carbon dioxide in the water cooler set reaches half of the volume of the water cooler set, carry out fluid filling and pressurization on the constant temperature water bath storage tank and the connected pipeline, until the state of carbon dioxide in the constant temperature water bath storage tank and the connected pipeline reaches the liquid state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, and then end the fluid filling and pressurization; Step S34, pipeline leakage test: when the pressure in the pipeline is higher than the burst pressure of 10 MPa, realize instantaneous leakage. Step S32, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 0℃; Step S33, fluid filling and pressurization: when the volume of liquid carbon dioxide in the water cooling unit is half of the volume of the water cooling unit, the constant temperature water bath storage tank and the connecting pipeline are fluid filled and pressurized, until the state of carbon dioxide in the constant temperature water bath storage tank and the connecting pipeline reaches the supercritical state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, the fluid filling and pressurization is ended; Step S34, pipeline leakage test: liquid carbon dioxide enters the test pipeline, when the pressure in the pipeline is higher than the burst pressure of 4MPa, instantaneous leakage is realized.

6. The method for testing the leakage of carbon dioxide pipeline according to claim 2 or 3 or 4 or 5, characterized in that The buried gaseous carbon dioxide pipeline leakage experiment test is carried out according to the following steps: Step S41, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 30℃; Step S42, gas filling and pressurization: the gas supply pressure in the carbon dioxide cylinder is adjusted to 4.5MPa to 5.0MPa, the temperature is 20℃, the constant temperature water bath storage tank and the connecting pipeline are gas filled and pressurized, until the state of carbon dioxide in the constant temperature water bath storage tank and the connecting pipeline reaches the gas state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, the gas filling and pressurization is ended; Step S43, pipeline leakage test: liquid carbon dioxide enters the test pipeline, when the pressure in the pipeline is higher than the burst pressure of 4MPa, instantaneous leakage is realized.

7. A device for use in a method of testing for leaks in a carbon dioxide pipeline according to any one of claims 1 to 6, characterised in that The buried gaseous carbon dioxide pipeline leakage experiment test is carried out according to the following steps:

8. The apparatus of claim 7, wherein Step S41, experimental temperature regulation: start the constant temperature water bath storage tank and the constant temperature water bath connected pipeline, wherein the constant temperature water bath temperature is 30℃; Step S42, gas filling and pressurization: the gas supply pressure in the carbon dioxide cylinder is adjusted to 4.5MPa to 5.0MPa, the temperature is 20℃, the constant temperature water bath storage tank and the connecting pipeline are gas filled and pressurized, until the state of carbon dioxide in the constant temperature water bath storage tank and the connecting pipeline reaches the gas state required by the experiment, and the volume of carbon dioxide in the constant temperature water bath storage tank reaches two-thirds of the volume of the constant temperature water bath storage tank, the gas filling and pressurization is ended; Step S43, pipeline leakage test: liquid carbon dioxide enters the test pipeline, when the pressure in the pipeline is higher than the burst pressure of 4MPa, instantaneous leakage is realized. A carbon dioxide cylinder, a three-way valve, a constant temperature water bath storage tank and a sand box are included, a cylinder outlet pipeline is fixedly communicated between the top outlet of the carbon dioxide cylinder and the upper port of the three-way valve, a liquid carbon dioxide generating pipeline is fixedly communicated between the right port of the three-way valve and the inlet of the constant temperature water bath storage tank, a gaseous carbon dioxide pipeline is fixedly communicated between the lower port of the three-way valve and the liquid carbon dioxide generating pipeline, a connecting pipeline is fixedly communicated between the outlet of the constant temperature water bath storage tank and the inlet of the sand box, a test pipeline is arranged in the sand box, and the outlet of the connecting pipeline is fixedly communicated with the inlet of the test pipeline. A water cooling machine and a liquid piston pump are fixedly installed on the liquid carbon dioxide generating pipeline, a first electric ball valve, a first pressure sensor and a first temperature sensor are fixedly installed on the liquid carbon dioxide generating pipeline between the right port of the three-way valve and the water cooling machine along the medium flow direction, a second pressure sensor, a second temperature sensor, a second vortex flowmeter and a second electric ball valve are fixedly installed on the liquid carbon dioxide generating pipeline between the liquid piston pump and the gaseous carbon dioxide pipeline along the medium flow direction, a third electric ball valve is fixedly installed on the gaseous carbon dioxide pipeline, a pneumatic ball valve is fixedly installed on the connecting pipeline, a flow regulating valve and a first vortex flowmeter are fixedly installed on the cylinder outlet pipeline along the medium flow direction, and a third pressure sensor and a third temperature sensor are arranged on the top of the constant temperature water bath storage tank.

9. The apparatus of claim 7 or 8, wherein The temperature sensor group, the safety protection device, the fourth pressure sensor and the fourth temperature sensor are fixedly installed on the test pipeline in sequence along the medium flow direction, and a blind plate is arranged at the outlet of the test pipeline.

10. The apparatus of claim 7 or 8 or 9, characterized in that The controller, the constant-temperature water bath storage tank, the flow regulating valve, the first vortex flowmeter, the liquid piston pump, the first electric ball valve, the first pressure sensor, the first temperature sensor, the second pressure sensor, the second temperature sensor, the second vortex flowmeter, the second electric ball valve, the third electric ball valve, the pneumatic ball valve, the temperature sensor group, the third pressure sensor, the third temperature sensor, the fourth pressure sensor and the fourth temperature sensor are electrically connected with the controller.

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