A device for testing the migration law of hydrates and sulfur particles in throttling process pipelines

Abstract

The present invention discloses a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline, and belongs to the technical field of natural gas hydrate testing. The device includes a natural gas filling system, a sulfur particle filling system, a water filling system, a hydrate preparation system, a gas-liquid-solid phase separation and transportation system, a water bath temperature control system, a transparent testing system, a separation circulation system, a particle tracing image velocimetry system, and a recovery unit. The device uses pressure difference boosting and screw feeding to achieve precise filling of sulfur particles in a pressurized pipeline; a two-stage throttling process design is used to simulate the rapid migration of hydrates and sulfur particles in the upstream and downstream pipelines of a multi-stage throttling valve; and a particle tracing image velocimetry system can be used to test the size morphology, migration trajectory, particle axial displacement speed, and deposition speed of hydrates and sulfur particles and their agglomerates. The device not only supports one-time passing test and circulating flow test of a mixture of hydrates and sulfur particles, but also supports the migration law test of hydrate particles dominated by water or gas.

Description

Technical Field

[0001] The invention relates to a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline, and relates to the technical field of natural gas hydrate testing. Background Art

[0002] The gas production of sour gas fields in my country accounts for more than 60% of the national natural gas production, and some gas fields are ultra-high pressure sour gas fields with wellhead pressure exceeding 100MPa. This type of ultra-high pressure sour natural gas is prone to form hydrates under high pressure and low temperature during wellhead throttling and pipeline transportation; in addition, the sulfur-containing substances in the local fluid are also prone to precipitate sulfur in the ground gathering and transportation system, resulting in the formation of a particle flow composed of hydrates and sulfur particles at local flow mutation points such as before and after the throttle valve and elbows. Observing their particle morphology, particle size distribution, and the migration and blockage laws of particle aggregates in the throttling process pipeline and gathering and transportation pipeline is of great value for the prediction and prevention of blockage of high-pressure sour natural gas hydrates.

[0003] Different from general technologies, the difficulties in testing the migration and blockage laws of hydrates and sulfur particles in throttling process pipelines include: ① Under certain conditions, high-pressure sour natural gas will have multiphase flow with hydrate particles, sulfur particles, natural gas and liquid coexisting during wellhead throttling and ground gathering and transportation. The technical solutions disclosed in CN115788420A and CN102865066B are mainly aimed at simulating the multiphase flow and hydrate blockage of hydrates in the wellbore, and cannot achieve the particle migration simulation of hydrate particles and sulfur particles coexisting; in particular, there are scenes such as throttling, pipeline fluctuations, and sudden changes in pipe flow direction in the gathering and transportation pipeline, and there are also significant differences in the migration laws of hydrates in the wellbore and the ground gathering and transportation system. ② High-pressure sour natural gas has the characteristics of large pressure difference, fast flow rate, and low temperature during the throttling process. The migration law of hydrate particles, sulfur particles, natural gas, and liquid mixtures formed before and after the throttling valve is very complicated. It is difficult for existing testing methods to reproduce the movement characteristics of low-temperature media in the upstream and downstream pipelines of multi-stage throttling valves. ③ The sulfur particles carried in the gas field throttling process pipeline are wet particles with small particle size and high viscosity; in the existing testing technology, dry sulfur powder is usually added to the pipeline to simulate the migration law of sulfur particles, which is not only difficult to control the amount of sulfur powder added, but also easy to block the feeding pipeline, resulting in a large deviation between the experimental test results and the experimental set values. ④ In actual throttling valves and gathering pipelines, the size, concentration and migration law of sulfur particles and hydrate particles are usually affected by factors such as temperature, pressure, and flow rate. The existing experimental equipment is difficult to control the concentration of particles (hydrates and sulfur) in the flow pipeline, and it is also difficult to observe the collision and rupture behavior of multiple particles and the changes in particle size morphology, particle axial displacement velocity and deposition velocity caused by the changes in particle migration laws. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline. The device can realize the simulation of particle flow migration of sulfur particles and hydrates coexisting by designing a sulfur particle filling system and a hydrate preparation system; by designing a sulfur particle filling system with pressure difference boosting and screw feeding functions, the precise filling of sulfur particles in a pressurized pipeline can be realized; by designing a water bath temperature control system and a transparent test pipeline with two-stage throttling, the rapid migration of low-temperature solid particles in pipelines upstream and downstream of a multi-stage throttling valve can be simulated; by designing a particle tracing image velocimetry system, the size morphology, migration trajectory, particle axial displacement speed and deposition speed of hydrates and sulfur particles and their agglomerates in pipelines upstream and downstream of the throttling valve can be tested.

[0005] The technical solution adopted by the present invention is:

[0006] A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline, comprising a natural gas filling system, a sulfur particle filling system, a water filling system, a hydrate preparation system, a gas-liquid-solid phase separation system, a water bath temperature control system, a transparent testing system, a separation circulation system, a particle tracing image velocity measurement system, and a recovery unit;

[0007] The natural gas filling system is led out from the gas cylinder 1, connected in sequence to the 1# valve 2, the compressor 3, the 4# valve 12, the 2# pressure gauge 13, the 2# temperature gauge 14, the 2# gas flow meter 15, and then connected to the upper gas inlet of the reactor 16;

[0008] The sulfur particle filling system is led out from the gas outlet of the compressor 3, passes through the 2# valve 4, the 1# pressure gauge 5, the 1# temperature gauge 6, the 1# gas flow meter 7, the sulfur particle filling device 8 and the 3# valve 9 in sequence, and is connected to the pipeline between the 4# temperature gauge 35 and the 1# hose 38; the sulfur particle filling device 8 is a sealing device with an open top and a motor 10 and a screw 11 installed inside;

[0009] The water filling system is led from the water storage tank 22, and is connected to the liquid inlet at the bottom of the reactor 16 after passing through the liquid flow meter 23, the water delivery pump 24, and the 5# valve 25 in sequence;

[0010] The hydrate preparation system is composed of a reactor 16, an agitator 17 installed on the reactor 16, a visual window 18, a 3# pressure gauge 19, a 3# temperature gauge 20 and a controllable temperature water bath 21; the visual window 18 can observe the growth state of the hydrate in the reactor 16 in real time; the bottom of the reactor 16 is connected to a 6# valve 26 and a sewage tank 27 in sequence;

[0011] The gas-liquid-solid phase transmission system includes a gas booster pipeline and a liquid-solid booster pipeline; the gas booster pipeline is led out from the gas outlet at the top of the reactor 16, and is connected in sequence to the 9# valve 31, the gas booster pump 32, the 10# valve 33, the 4# pressure gauge 34 and the 4# temperature gauge 35; the liquid-solid booster pipeline is led out from the lower outlet of the reactor 16, and is connected to the intermediate pipeline between the 10# valve 33 and the 4# pressure gauge 34 after passing through the 7# valve 28, the multiphase mixed transmission pump 29 and the 8# valve 30 in sequence;

[0012] The water bath temperature control system includes a controllable temperature water bath 21, a 1# circulating water bath control box 36, a circulating water bath pipeline 37, and a 2# circulating water bath control box 72; the controllable temperature water bath 21 can control the temperature in the reactor 16; the circulating water bath pipeline 37 is installed on the outer surface of the pipeline of the gas-liquid-solid phase separation and transportation system; the 1# circulating water bath control box 36 can control the temperature of the fluid in the pipeline of the gas-liquid-solid phase separation and transportation system through the circulating water bath pipeline 37; the 2# circulating water bath control box 72 realizes the temperature control of the transparent test system and the separation circulation system by laying a temperature tracing pipeline on the outer surface of the pipeline of the transparent test system and the separation circulation system;

[0013] The transparent test system is composed of a 1# hose 38, a 1# throttle valve 39, a 1# transparent pipe section 40, a 2# throttle valve 41, a 2# transparent pipe section 42, and a 2# hose 45 connected in sequence; the 1# transparent pipe section 40 is connected to a rotating support frame 44; the 2# throttle valve 41 is detachable and replaceable with a U-shaped pipe section 43;

[0014] The separation circulation system is composed of a 5# pressure gauge 46, a 5# temperature gauge 47, a 11# valve 48, a separator 49, a 19# valve 70, and a 13# valve 51 connected in sequence; one end of the separation circulation system is connected to the 2# transparent pipe section 42 in the transparent test system through a 2# hose 45, and the other end is connected to the pipeline between the 4# valve 12 and the 2# pressure gauge 13; the separation circulation system is also provided with a bypass pipeline and a circulation pipeline; the bypass pipeline is led out from the pipeline between the 11# valve 48 and the separator 49, and is connected to the 17# valve 51 in sequence. # valve 68, 18# valve 69 are connected to the pipeline between 19# valve 70 and 13# valve 51; one end of the natural gas recovery tank 66 is connected to the pipeline between the separator 49 and 13# valve 51 through 12# valve 50, and the other end is connected to the pipeline between 1# valve 2 and compressor 3 through 16# valve 67; the circulation pipeline is led out from the liquid-solid booster pipeline between 7# valve 28 and multiphase mixed transport pump 29, and connected to the pipeline between 19# valve 70 and 13# valve 51 after passing through 20# valve 71;

[0015] The recovery unit is led out from the bottom of the separator 49 and connected to the inlet of the centrifugal solid-liquid separator 53 through the 14# valve 52; the liquid outlet at the top of the centrifugal solid-liquid separator 53 is connected to the liquid storage tank 55 through the 15# valve 54, and the solid outlet at the bottom is connected to the sulfur particle recovery tank 56; one end of the 20# valve 71 is connected to the liquid-solid booster pipeline between the 7# valve 28 and the multiphase mixed transport pump 29, and the other end is connected to the pipeline between the 19# valve 70 and the 13# valve 51;

[0016] The particle tracing image velocimetry system comprises a water storage tank 22, a sulfur particle filling device 8, a first particle image velocimetry system and a second particle image velocimetry system; the water storage tank 22 is provided with liquid tracer particles, and the sulfur particle filling device 8 is provided with solid particle fluorescent tracer powder of a color different from that of the liquid tracer particles; the first particle image velocimetry system is connected in sequence to a 1# synchronous controller 58, a 1# laser emitter 60 and a 1# optical lens 61 after being led out by a computer 57; a 1# high-definition camera 59 is connected to the top of the 1# synchronous controller 58; the second particle image velocimetry system is connected in sequence to a 2# synchronous controller 62, a 2# laser emitter 64 and a 2# optical lens 65 after being led out by a computer 57; and a 2# high-definition camera 63 is connected to the top of the 2# synchronous controller 62.

[0017] Furthermore, a 2# gas flow meter 15 is installed on the pipeline of the natural gas filling system, and a liquid flow meter 23 is installed on the pipeline of the water filling system. The pressure and ratio of the natural gas and water injected into the reactor 16 can be controlled by controlling the compressor 3 and the water pump 24 respectively; at the same time, by controlling the rotation speed of the agitator 17 and the refrigeration power of the controllable temperature water bath 21, the temperature and pressure of the medium in the reactor 16 and the mass transfer rate of the natural gas and water are adjusted to generate natural gas hydrate.

[0018] Furthermore, two-color liquid tracer particles and solid particle fluorescent tracer powder are used to mark the natural gas hydrate particles and sulfur particles. Using the first particle image velocimetry system and the second particle image velocimetry system, the size morphology, migration trajectory, particle axial displacement velocity and deposition velocity of the hydrate particles, sulfur particles and their agglomerates can be observed. The collision and rupture process of particle agglomerates and the migration laws of hydrates and sulfur particles can be photographed.

[0019] Furthermore, the sulfur particle filling system can increase the pressure in the sulfur particle filling device through the compressor 3, making it higher than the pressure in the gas-liquid-solid phase distribution system pipeline downstream of the 3# valve 9 by 0.02MPa, thereby forming a sulfur particle boosting pressure difference. At the same time, the motor 10 drives the screw 11 to rotate and feed the material, and injects the sulfur particles in the sulfur particle filling device 8 into the gas-liquid-solid phase distribution system pipeline to prevent the sulfur particles from adhering to and clogging the pipeline.

[0020] Furthermore, the sulfur particle filling device 8 and the 3# valve 9 in the sulfur particle filling system are connected to the pipeline between the 4# temperature gauge 35 and the 1# hose 38 in a vertical direction to the ground, and the sulfur particle filling device 8 is connected to the gas-liquid-solid phase distribution system pipeline with a vertical pipeline, which can reduce the adhesion of sulfur particles to the sulfur particle filling pipeline.

[0021] Furthermore, the 1# transparent pipe section 40, the 2# transparent pipe section 42 and the U-shaped pipe section 43 are made of pressure-resistant transparent materials; the 1# throttle valve 39 and the 2# throttle valve 41 are electric regulating valves, which can accurately adjust the opening of the 1# throttle valve 39 and the 2# throttle valve 41 respectively, so that different pressure differences and flow rates are generated in the 1# transparent pipe section 40 and the 2# transparent pipe section 42.

[0022] Furthermore, the gas in the hydrate preparation system flows out from the top pipeline of the reactor 16, and the liquid-solid mixture flows out from the lower outlet of the reactor 16, and the two merge in the pipeline between the 8# valve 30 and the 10# valve 33 to form a mixture composed of gas, liquid and solid phases; the sulfur particles in the sulfur particle filling system pass through the 3# valve 9, and are mixed again with the gas, liquid and solid phase mixture formed in the hydrate preparation system, and then enter the transparent test system composed of the 1# hose 38, the 1# throttle valve 39, the 1# transparent pipe section 40, the 2# throttle valve 41, and the 2# transparent pipe section 42, so that the migration law test of the gas, liquid and solid phase medium with two kinds of particles coexisting can be realized; one end of the rotating support frame 44 is vertically installed on the ground, and the other end is installed on the 1# transparent pipe section 40, and the rotating support frame 44 can rotate at an acute angle with the ground plane within the range of 0°-45°, so as to realize the migration law test of sulfur-containing natural gas hydrate in the inclined pipeline.

[0023] Furthermore, by changing the refrigeration power of the controllable temperature water bath 21 and the 1# circulating water bath control box 36 and adjusting the supercooling degree of the fluid in the reactor 16, the growth rate of the hydrate in the reactor 16 and the gas-liquid-solid phase distribution system pipeline can be controlled, thereby changing the hydrate volume concentration; by controlling the opening of the 3# valve 9 in the sulfur particle filling system to adjust the filling amount of sulfur particles, the volume concentration of particles in the transparent test system pipeline can be adjusted.

[0024] Furthermore, the gas-liquid-solid phase separation and transportation system includes a gas booster pipeline and a liquid-solid booster pipeline. The migration law of natural gas hydrate dominated by water in the pipeline can be tested by fully opening the gas-liquid-solid phase separation and transportation system, or the migration law of water-containing natural gas hydrate dominated by natural gas in the pipeline can be tested by only opening the gas booster pipeline; by fully opening the gas-liquid-solid phase separation and transportation system pipeline or only opening the gas booster pipeline, flexible switching between the multiphase flow migration law tests of hydrate particles dominated by water or natural gas in the pipeline can be achieved.

[0025] The present invention adopts the above technical solution, and can achieve the following beneficial effects:

[0026] (1) The present invention generates a sufficient amount of hydrate particles through a hydrate preparation system with a stirrer; the pressure difference between the sulfur particle filling device and the gas-liquid-solid phase distribution system pipeline is adjusted by a compressor to form a boosting force for particle filling; on this basis, a motor is used to drive a screw to rotate and feed the material, thereby realizing accurate filling of sulfur particles into the high-pressure flow pipeline, avoiding the problem of blockage of the feeding pipeline, and providing test conditions for the particle flow migration of sulfur particles and hydrates coexisting.

[0027] (2) By using the designed transparent test system with two-stage throttling function, the pump speed, throttle valve opening and circulating water bath temperature upstream of the transparent test system can be adjusted to simulate the migration and blockage process of hydrate particles and sulfur particles coexisting in the particle flow before and after the throttle valve at different flow rates, pressure differences and temperatures in the wellhead throttling process pipeline and gathering and transportation system of high-pressure sulfur-containing gas fields. The fluorescent tracers and tracer ions in the particle tracer image velocimetry system are used to trace and mark the hydrate and sulfur particles. Further combined with high-speed imaging equipment, not only the size morphology, migration trajectory, axial displacement velocity and deposition velocity of hydrate particles and sulfur particles and their aggregates can be observed, but also the collision and rupture process of single particles and aggregates, as well as the migration law of hydrate and sulfur particles and the degree of pipeline blockage can be captured.

[0028] (3) By adjusting the difference between the temperature of the fluid in the reactor or tube and the hydrate formation temperature through the water bath temperature control system, the hydrate growth, decomposition rate and the corresponding hydrate concentration can be controlled; by controlling the motor speed of the sulfur particle filling device, the sulfur particle filling rate can be controlled, thereby adjusting the sulfur particle concentration in the transparent test system. The above scheme realizes the control of the particle concentration in the transparent test system pipeline, which is convenient for experimental tests under different solid concentrations.

[0029] (4) By generating a sufficient amount of hydrate particles in the hydrate preparation system, adding a sufficient amount of sulfur particles to the sulfur particle filling device, cutting off the bypass pipeline, opening the separator and the natural gas and sulfur particle recovery device, the migration law of the hydrate particles and sulfur particles mixture can be tested once, which can more realistically simulate the migration law of particles in the throttling process pipeline; by connecting the bypass pipeline, closing the separator and the natural gas and sulfur particle recovery device, the circulation flow test of the hydrate particles and sulfur particles mixture can be realized, and the continuous test of the particle migration law can be achieved.

[0030] (5) The designed gas cylinders and water storage tanks can be used to adjust the volume ratio of gas and water in the reactor to achieve the test of hydrate migration law dominated by water or gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1It is a structural schematic diagram of a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline of the present invention.

[0032] In the figure: gas cylinder 1, 1# valve 2, compressor 3, 2# valve 4, 1# pressure gauge 5, 1# temperature gauge 6, 1# gas flow meter 7, sulfur particle filling device 8, 3# valve 9, motor 10, screw 11, 4# valve 12, 2# pressure gauge 13, 2# temperature gauge 14, 2# gas flow meter 15, reactor 16, stirrer 17, visual window 18, 3# pressure gauge 19, 3# temperature gauge 20, controllable temperature water bath 21, water storage tank 22, liquid flow meter 23, water delivery pump 24, 5# valve 25, 6# valve 26, sewage tank 27, 7# valve 28, multiphase mixed delivery pump 29, 8# valve 30, 9# valve 31, gas booster pump 32, 10# valve 33, 4# pressure gauge 34, 4# temperature gauge 35, 1# circulating water bath control box 36, circulating water bath pipeline 37, 1# hose 38, 1# throttle valve 39, 1# transparent pipe section 40, 2# throttle valve 41, 2# transparent pipe section 42, U-shaped pipe section 43, rotating support frame 44, 2# hose 45, 5# pressure gauge 46, 5# temperature gauge 47, 11# valve 48, separator 49, 12# valve 50, 13# valve 51, 14# valve 52, centrifugal solid-liquid separator 53, 15# valve 54, liquid storage tank 55, sulfur particle recovery tank 56, computer 57, 1# synchronous controller 58, 1# high-definition camera 59, 1# laser transmitter 60, 1# optical lens 61, 2# synchronous controller 62, 2# high-definition camera 63, 2# laser transmitter 64, 2# optical lens 65, natural gas recovery tank 66, 16# valve 67, 17# valve 68, 18# valve 69, 19# valve 70, 20# valve 71, 2# circulating water bath control box 72. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, specific implementation methods of the present invention are now described with reference to the accompanying drawings, but the protection scope of the present invention is not limited to the following.

[0034] The terms "open" and "close" are used to indicate the start and stop actions of the working status of all kinds of valves, meters, flow meters, separators, compressors, pumps and other equipment that can be opened or closed within the object. When a pipeline is opened, it means that the equipment connected in the middle of the pipeline is in normal working condition and the fluid in the pipeline can flow; when a pipeline is closed, it means that the equipment connected in the middle of the pipeline is in a stopped working state and the fluid in the pipeline cannot flow.

[0035] As attached Figure 1, a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline, including a natural gas filling system, a sulfur particle filling system, a water filling system, a hydrate preparation system, a gas-liquid-solid phase separation system, a water bath temperature control system, a transparent test system, a separation circulation system, a particle tracer image velocity measurement system, and a recovery unit;

[0036] The technical solution adopted by the present invention is:

[0037] The natural gas filling system is led out from the gas cylinder 1, connected in sequence to the 1# valve 2, the compressor 3, the 4# valve 12, the 2# pressure gauge 13, the 2# temperature gauge 14, the 2# gas flow meter 15, and then connected to the upper gas inlet of the reactor 16;

[0038] The sulfur particle filling system is led out from the gas outlet of the compressor 3, passes through the 2# valve 4, the 1# pressure gauge 5, the 1# temperature gauge 6, the 1# gas flow meter 7, the sulfur particle filling device 8 and the 3# valve 9 in sequence, and is connected to the pipeline between the 4# temperature gauge 35 and the 1# hose 38; the sulfur particle filling device 8 is a sealing device with an open top and a motor 10 and a screw 11 installed inside;

[0039] The water filling system is led from the water storage tank 22, and is connected to the liquid inlet at the bottom of the reactor 16 after passing through the liquid flow meter 23, the water delivery pump 24, and the 5# valve 25 in sequence;

[0040] The hydrate preparation system is composed of a reactor 16, an agitator 17 installed on the reactor 16, a visual window 18, a 3# pressure gauge 19, a 3# temperature gauge 20 and a controllable temperature water bath 21; the visual window 18 can observe the growth state of the hydrate in the reactor 16 in real time; the bottom of the reactor 16 is connected to a 6# valve 26 and a sewage tank 27 in sequence;

[0041] The gas-liquid-solid phase transmission system includes a gas booster pipeline and a liquid-solid booster pipeline; the gas booster pipeline is led out from the gas outlet at the top of the reactor 16, and is connected in sequence to the 9# valve 31, the gas booster pump 32, the 10# valve 33, the 4# pressure gauge 34 and the 4# temperature gauge 35; the liquid-solid booster pipeline is led out from the lower outlet of the reactor 16, and is connected to the intermediate pipeline between the 10# valve 33 and the 4# pressure gauge 34 after passing through the 7# valve 28, the multiphase mixed transmission pump 29 and the 8# valve 30 in sequence;

[0042] The water bath temperature control system includes a controllable temperature water bath 21, a 1# circulating water bath control box 36, a circulating water bath pipeline 37, and a 2# circulating water bath control box 72; the controllable temperature water bath 21 can control the temperature in the reactor 16; the circulating water bath pipeline 37 is installed on the outer surface of the pipeline of the gas-liquid-solid phase separation and transportation system; the 1# circulating water bath control box 36 can control the temperature of the fluid in the pipeline of the gas-liquid-solid phase separation and transportation system through the circulating water bath pipeline 37; the 2# circulating water bath control box 72 realizes the temperature control of the transparent test system and the separation circulation system by laying a temperature tracing pipeline on the outer surface of the pipeline of the transparent test system and the separation circulation system;

[0043] The transparent test system is composed of a 1# hose 38, a 1# throttle valve 39, a 1# transparent pipe section 40, a 2# throttle valve 41, a 2# transparent pipe section 42, and a 2# hose 45 connected in sequence; the 1# transparent pipe section 40 is connected to a rotating support frame 44; the 2# throttle valve 41 is detachable and replaceable with a U-shaped pipe section 43;

[0044] The separation circulation system is composed of a 5# pressure gauge 46, a 5# temperature gauge 47, a 11# valve 48, a separator 49, a 19# valve 70, and a 13# valve 51 connected in sequence; one end of the separation circulation system is connected to the 2# transparent pipe section 42 in the transparent test system through a 2# hose 45, and the other end is connected to the pipeline between the 4# valve 12 and the 2# pressure gauge 13; the separation circulation system is also provided with a bypass pipeline and a circulation pipeline; the bypass pipeline is led out from the pipeline between the 11# valve 48 and the separator 49, and is connected to the 17# valve 51 in sequence. # valve 68, 18# valve 69 are connected to the pipeline between 19# valve 70 and 13# valve 51; one end of the natural gas recovery tank 66 is connected to the pipeline between the separator 49 and 13# valve 51 through 12# valve 50, and the other end is connected to the pipeline between 1# valve 2 and compressor 3 through 16# valve 67; the circulation pipeline is led out from the liquid-solid booster pipeline between 7# valve 28 and multiphase mixed transport pump 29, and connected to the pipeline between 19# valve 70 and 13# valve 51 after passing through 20# valve 71;

[0045] The recovery unit is led out from the bottom of the separator 49 and connected to the inlet of the centrifugal solid-liquid separator 53 through the 14# valve 52; the liquid outlet at the top of the centrifugal solid-liquid separator 53 is connected to the liquid storage tank 55 through the 15# valve 54, and the solid outlet at the bottom is connected to the sulfur particle recovery tank 56; one end of the 20# valve 71 is connected to the liquid-solid booster pipeline between the 7# valve 28 and the multiphase mixed transport pump 29, and the other end is connected to the pipeline between the 19# valve 70 and the 13# valve 51;

[0046] The particle tracing image velocimetry system comprises a water storage tank 22, a sulfur particle filling device 8, a first particle image velocimetry system and a second particle image velocimetry system; the water storage tank 22 is provided with liquid tracer particles, and the sulfur particle filling device 8 is provided with solid particle fluorescent tracer powder of a color different from that of the liquid tracer particles; the first particle image velocimetry system is connected in sequence to a 1# synchronous controller 58, a 1# laser emitter 60 and a 1# optical lens 61 after being led out by a computer 57; a 1# high-definition camera 59 is connected to the top of the 1# synchronous controller 58; the second particle image velocimetry system is connected in sequence to a 2# synchronous controller 62, a 2# laser emitter 64 and a 2# optical lens 65 after being led out by a computer 57; and a 2# high-definition camera 63 is connected to the top of the 2# synchronous controller 62.

[0047] Furthermore, a 2# gas flow meter 15 is installed on the pipeline of the natural gas filling system, and a liquid flow meter 23 is installed on the pipeline of the water filling system. The pressure and ratio of the natural gas and water injected into the reactor 16 can be controlled by controlling the compressor 3 and the water pump 24 respectively; at the same time, by controlling the rotation speed of the agitator 17 and the refrigeration power of the controllable temperature water bath 21, the temperature and pressure of the medium in the reactor 16 and the mass transfer rate of the natural gas and water are adjusted to generate natural gas hydrate.

[0048] Furthermore, two-color liquid tracer particles and solid particle fluorescent tracer powder are used to mark the natural gas hydrate particles and sulfur particles. Using the first particle image velocimetry system and the second particle image velocimetry system, the size morphology, migration trajectory, particle axial displacement velocity and deposition velocity of the hydrate particles, sulfur particles and their agglomerates can be observed. The collision and rupture process of particle agglomerates and the migration laws of hydrates and sulfur particles can be photographed.

[0049] Furthermore, the sulfur particle filling system can increase the pressure in the sulfur particle filling device through the compressor 3, making it higher than the pressure in the gas-liquid-solid phase distribution system pipeline downstream of the 3# valve 9 by 0.02MPa, thereby forming a sulfur particle boosting pressure difference. At the same time, the motor 10 drives the screw 11 to rotate and feed the material, and injects the sulfur particles in the sulfur particle filling device 8 into the gas-liquid-solid phase distribution system pipeline to prevent the sulfur particles from adhering to and clogging the pipeline.

[0050] Furthermore, the sulfur particle filling device 8 and the 3# valve 9 in the sulfur particle filling system are connected to the pipeline between the 4# temperature gauge 35 and the 1# hose 38 in a vertical direction to the ground, and the sulfur particle filling device 8 is connected to the gas-liquid-solid phase distribution system pipeline with a vertical pipeline, which can reduce the adhesion of sulfur particles to the sulfur particle filling pipeline.

[0051] Furthermore, the 1# transparent pipe section 40, the 2# transparent pipe section 42 and the U-shaped pipe section 43 are made of pressure-resistant transparent materials; the 1# throttle valve 39 and the 2# throttle valve 41 are electric regulating valves, which can accurately adjust the opening of the 1# throttle valve 39 and the 2# throttle valve 41 respectively, so that different pressure differences and flow rates are generated in the 1# transparent pipe section 40 and the 2# transparent pipe section 42.

[0052] Furthermore, the gas in the hydrate preparation system flows out from the top pipeline of the reactor 16, and the liquid-solid mixture flows out from the lower outlet of the reactor 16, and the two merge in the pipeline between the 8# valve 30 and the 10# valve 33 to form a mixture composed of gas, liquid and solid phases; the sulfur particles in the sulfur particle filling system pass through the 3# valve 9, and are mixed again with the gas, liquid and solid phase mixture formed in the hydrate preparation system, and then enter the transparent test system composed of the 1# hose 38, the 1# throttle valve 39, the 1# transparent pipe section 40, the 2# throttle valve 41, and the 2# transparent pipe section 42, so that the migration law test of the gas, liquid and solid phase medium with two kinds of particles coexisting can be realized; one end of the rotating support frame 44 is vertically installed on the ground, and the other end is installed on the 1# transparent pipe section 40, and the rotating support frame 44 can rotate at an acute angle with the ground plane within the range of 0°-45°, so as to realize the migration law test of sulfur-containing natural gas hydrate in the inclined pipeline.

[0053] Furthermore, by changing the refrigeration power of the controllable temperature water bath 21 and the 1# circulating water bath control box 36 and adjusting the supercooling degree of the fluid in the reactor 16, the growth rate of the hydrate in the reactor 16 and the gas-liquid-solid phase distribution system pipeline can be controlled, thereby changing the hydrate volume concentration; by controlling the opening of the 3# valve 9 in the sulfur particle filling system to adjust the filling amount of sulfur particles, the volume concentration of particles in the transparent test system pipeline can be adjusted.

[0054] Furthermore, the gas-liquid-solid phase separation and transportation system includes a gas booster pipeline and a liquid-solid booster pipeline. The migration law of natural gas hydrate dominated by water in the pipeline can be tested by fully opening the gas-liquid-solid phase separation and transportation system, or the migration law of water-containing natural gas hydrate dominated by natural gas in the pipeline can be tested by only opening the gas booster pipeline; by fully opening the gas-liquid-solid phase separation and transportation system pipeline or only opening the gas booster pipeline, flexible switching between the multiphase flow migration law tests of hydrate particles dominated by water or natural gas in the pipeline can be achieved.

[0055] Example 1: Take the simulated test of the gathering and transportation pipeline with the working conditions of 5MPa pipeline inlet pressure, two-stage throttling, 30g sulfur addition, uphill pipe type and 30° angle between the pipeline and the ground plane as an example; Figure 1 As shown, a device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline is described. The specific steps for testing the migration law of sulfur-containing natural gas hydrate particles dominated by water under this working condition are as follows:

[0056] S101, according to the experimental requirements, the operating conditions of the gathering and transportation pipeline to be simulated are determined as follows: the inlet pressure is 5 MPa, the throttling process is secondary throttling, the sulfur addition amount is 30 g, the pipe type is uphill, and the angle between the pipe and the ground plane is 30°.

[0057] S102, open the controllable temperature water bath 21 to precool the inside of the reactor 16 to 5.0°C, open the water filling system, and add an appropriate amount of water containing uniformly distributed tracer particles into the reactor 16 according to experimental requirements; turn on the agitator 17, close the water filling system, and open the natural gas filling system. When the pressure in the reactor 16 reaches 4MPa, close the natural gas filling system and adjust the controllable temperature water bath 21 to reduce the internal temperature of the reactor 16 to 0.5°C.

[0058] S103, real-time observation of the temperature and pressure values ​​in the reactor 16, when the pressure in the reactor 16 drops to 3MPa, the natural gas filling system is opened again to add natural gas, and when the pressure in the reactor 16 reaches 4MPa, the natural gas filling system is closed; the pressure in the reactor 16 is maintained at 4MPa and the temperature is maintained at 0.5°C by repeatedly opening or closing the natural gas filling system and adjusting the controllable temperature water bath 21, until the amount of natural gas hydrate generated meets the experimental requirements as observed through the visual window 18, the natural gas filling system and the agitator 17 are closed, and the temperature in the reactor 16 is adjusted to 3.4°C.

[0059] S104, open the 1# circulating water bath control box 36, precool the gas-liquid-solid phase distribution system to 3.4°C through the circulating water bath pipeline 37, turn on the particle tracer image velocimetry system, and adjust the openings of the 1# throttle valve 39 and the 2# throttle valve 41 to be fully open; open the 2# circulating water bath control box 72, the 11# valve 48, the 17# valve 68, the 18# valve 69, the 20# valve 71, and the liquid-solid booster pipeline in sequence, and suck the hydrate slurry in the reactor 16 into the gas-liquid-solid phase distribution system; open the gas booster pipeline, and suck the natural gas in the reactor 16 into the gas-liquid-solid phase distribution system.

[0060] S105, adjust the multiphase mixed delivery pump 29, gas booster pump 32 and 1# circulating water bath control box 36, 2# circulating water bath control box 72 to maintain the working state of 5MPa pressure and 3.4°C temperature in the gas-liquid-solid phase separation and delivery system, transparent testing system and separation circulation system; use the particle tracer image velocimetry system to collect the migration image of the unthrottled pure natural gas hydrate particles in the horizontal pipeline at this time.

[0061] S106, adjusting the rotating support frame 44 so that the transparent test system pipeline is uphill and the angle between the pipeline and the ground plane is 30°; using the particle tracer image velocimetry system to collect the migration image of the unthrottled pure natural gas hydrate particles in the 30° uphill pipeline.

[0062] S107, respectively adjust the openings of the 1# throttle valve 39 and the 2# throttle valve 41 to maintain the outlet pressure of the transparent test system pipeline at 2 MPa; use the particle tracer image velocimetry system to collect the migration image of pure natural gas hydrate particles in the upward 30° pipeline before and after the two-stage throttling and pressure reduction of 3 MPa.

[0063] S108, open the 13# valve 51, the separator 49, the recovery unit, and the 19# valve 70 in sequence, and close the 17# valve 68, the 18# valve 69, and the 20# valve 71 in sequence; open the sulfur particle filling device 8 and put in 30g of sulfur powder particles containing uniformly distributed fluorescent tracer powder; open the 1# valve 2, the 2# valve 4 and the compressor 3 in sequence to pressurize the natural gas in the sulfur particle filling system to 5.02MPa; open the motor 10 and the 3# valve 9 in sequence, adjust the motor speed to 100 rpm, and fill the sulfur powder particles into the gas-liquid-solid phase separation system through the pressure difference between the sulfur particle filling system and the gas boosting pipeline and the screw feeding; use the particle tracer image velocimetry system to collect the migration image of the sulfur-containing natural gas hydrate in the 30° upward pipeline before and after the two-stage throttling and pressure reduction of 3MPa.

[0064] S109, experimental data analysis, comparison of migration images of pure natural gas hydrate without throttling in horizontal and 30° upward-inclined pipelines, migration images of pure natural gas hydrate without throttling and with two-stage throttling in 30° upward-inclined pipelines, and migration images of pure natural gas and sour-containing natural gas hydrate in two-stage throttling pipelines at 30° upwards, image analysis of the size and morphology of hydrate particles and sulfur particles and their agglomerates, image analysis of the collision and rupture process of single hydrate particles and agglomerates, as well as the migration law of hydrates and sulfur particles and the degree of pipeline blockage, and the influence of pipeline inclination, throttling and pressure reduction, and sulfur-containing particles on the size and morphology, migration trajectory, particle axial displacement velocity, deposition velocity and deposition amount of natural gas hydrates in pipelines.

[0065] S110, after the experiment is over, the sulfur particle filling system, multiphase mixed delivery pump 29, 1# circulating water bath control box 36, 2# circulating water bath control box 72, and controllable temperature water bath box 21 are closed in sequence; 12# valve 50 is opened, 13# valve 51 is closed, and the separated natural gas is recovered into the natural gas recovery tank 66; the gas booster pump 32, 7# valve 28, 8# valve 30, 9# valve 31, 10# valve 33, 1# throttle valve 39, 2# throttle valve 41, and 11# valve 48 are closed in sequence to complete the cleaning and recovery of the fluids in the gas-liquid-solid phase separation and delivery system, the transparent test system, and the separation circulation system.

[0066] S111, close the 14# valve 52, the centrifugal solid-liquid separator 53, and the 15# valve 54 in sequence to complete the recovery of the separated liquid and sulfur particles; open the 6# valve 26, introduce the residual fluid at the bottom of the reactor 16 into the sewage tank 27, and close the 6# valve 26.

[0067] Example 2: The device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline can also simulate the rate and amount of natural gas hydrates generated by saturated water-containing natural gas dominated by natural gas after two-stage throttling in the pipeline. The specific operation steps are as follows:

[0068] S201, according to the experimental requirements, the natural gas pressure to be tested is determined to be 10MPa, the temperature is 2°C, and the amount of water to be added is 50L.

[0069] S202, open the water filling system, and inject 50L of water containing evenly distributed tracer particles into the reactor 16; close the water filling system; open the natural gas filling system, and inject natural gas into the reactor 16 until the pressure in the reactor 16 reaches 9MPa.

[0070] S203, open and adjust the controllable temperature water bath 21 to the temperature in the reactor 16 to 2°C; turn on the agitator 17 to stir for 1 hour to allow the high-pressure natural gas in the reactor 16 to fully contact with the water. At this time, the natural gas in the reactor 16 fully contains water; open and adjust the 1# circulating water bath control box 36 to preheat the temperature in the gas-liquid-solid phase distribution system pipeline to 2°C.

[0071] S204, open the separation circulation system, transparent test system, and gas booster pipeline in sequence, so that the high-pressure water-containing natural gas in the reactor 16 is pressurized by the gas booster pump 32, and then flows through the transparent test system and the separation circulation system in sequence and recirculates back to the reactor 16, forming a high-pressure water-containing natural gas circulation loop.

[0072] S205, turn on the particle tracing image velocity measurement system; adjust the operating power of the gas booster pump 32 and the 1# circulating water bath control box 36 to maintain the pressure of the water-containing natural gas in the circulation loop at 10 MPa and the temperature at 2°C.

[0073] S206, the opening of the 1# throttle valve 39 and the 2# throttle valve 41 is slowly adjusted from 100% to 50% in 5 equal times, and the next adjustment is performed 30 minutes after each adjustment. From the start of the adjustment of the opening, the display values ​​of the 5# pressure gauge 46 and the 5# temperature gauge 47 downstream of the transparent test system are recorded every 10 minutes, and the particle tracer image velocimetry system is used to collect the hydrate generation image in the transparent test system after the two-stage throttling and pressure reduction every 10 minutes.

[0074] S207, open 12# valve 50, close 13# valve 51, and recover the natural gas in the pipeline into the natural gas recovery tank 66; close the gas pressurization pipeline, transparent test system, separation circulation system and 12# valve 50 in sequence; close the particle tracing image velocimetry system; open 6# valve 26, introduce the residual fluid at the bottom of the reactor 16 into the sewage tank 27, and close 6# valve 26.

[0075] S208, experimental data analysis, by comparing 15 groups of test images, the corresponding rules of natural gas hydrate formation rate, generation amount and temperature and pressure drop values ​​after secondary throttling of saturated water-containing natural gas with a pressure of 10MPa and a temperature of 2°C are obtained.

[0076] Example 3: The device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline can also simulate the migration law of hydrate particles in the process of natural gas hydrates in the gathering and transportation pipeline passing through a local pipe fitting with a changed flow direction after the first-level throttling and pressure reduction by dismantling the 2# throttling valve 41 and replacing the U-shaped pipe section 43.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline, comprising a natural gas filling system, a sulfur particle filling system, a water filling system, a hydrate preparation system, a gas-liquid-solid phase separation system, a water bath temperature control system, a transparent testing system, a separation circulation system, a particle tracing image velocity measurement system, and a recovery unit; The natural gas filling system is led out from the gas cylinder (1), connected in sequence to the 1# valve (2), the compressor (3), the 4# valve (12), the 2# pressure gauge (13), the 2# temperature gauge (14), the 2# gas flow meter (15), and then connected to the upper gas inlet of the reactor (16); The sulfur particle filling system is led out from the gas outlet of the compressor (3), passes through the 2# valve (4), the 1# pressure gauge (5), the 1# temperature gauge (6), the 1# gas flow meter (7), the sulfur particle filling device (8) and the 3# valve (9) in sequence, and is connected to the pipeline between the 4# temperature gauge (35) and the 1# hose (38); the sulfur particle filling device (8) is a sealing device with an openable top and a motor (10) and a screw (11) installed inside; The water filling system is led out from the water storage tank (22), and is connected to the lower liquid inlet of the reaction kettle (16) after passing through the liquid flow meter (23), the water delivery pump (24), and the 5# valve (25) in sequence; The hydrate preparation system comprises a reaction kettle (16), an agitator (17) installed on the reaction kettle (16), a visual window (18), a 3# pressure gauge (19), a 3# temperature gauge (20) and a controllable temperature water bath (21); the visual window (18) can observe the growth state of the hydrate in the reaction kettle (16) in real time; the bottom of the reaction kettle (16) is connected in sequence with a 6# valve (26) and a waste tank (27); The gas-liquid-solid phase transmission system comprises a gas booster pipeline and a liquid-solid booster pipeline; the gas booster pipeline is led out from the gas outlet at the top of the reactor (16), and is connected in sequence to the 9# valve (31), the gas booster pump (32), the 10# valve (33), the 4# pressure gauge (34) and the 4# temperature gauge (35); the liquid-solid booster pipeline is led out from the lower outlet of the reactor (16), and is connected to the intermediate pipeline between the 10# valve (33) and the 4# pressure gauge (34) after passing through the 7# valve (28), the multiphase mixed transmission pump (29) and the 8# valve (30); The water bath temperature control system comprises a controllable temperature water bath (21), a No. 1 circulating water bath control box (36), a circulating water bath pipeline (37), and a No. 2 circulating water bath control box (72); the controllable temperature water bath (21) can control the temperature in the reaction kettle (16); the circulating water bath pipeline (37) is installed on the outer surface of the pipeline of the gas-liquid-solid phase separation and transportation system; the No. 1 circulating water bath control box (36) can control the temperature of the fluid in the pipeline of the gas-liquid-solid phase separation and transportation system through the circulating water bath pipeline (37); the No. 2 circulating water bath control box (72) realizes temperature control of the transparent test system and the separation circulation system by laying a temperature tracing pipeline on the outer surface of the pipeline of the transparent test system and the separation circulation system; The transparent testing system is composed of a 1# hose (38), a 1# throttle valve (39), a 1# transparent pipe section (40), a 2# throttle valve (41), a 2# transparent pipe section (42), and a 2# hose (45) connected in sequence; the 1# transparent pipe section (40) is connected to a rotating support frame (44); the 2# throttle valve (41) is detachable and replaceable with a U-shaped pipe section (43); The separation circulation system is composed of a 5# pressure gauge (46), a 5# temperature gauge (47), a 11# valve (48), a separator (49), a 19# valve (70), and a 13# valve (51) which are connected in sequence; one end of the separation circulation system is connected to the 2# transparent pipe section (42) in the transparent test system through a 2# hose (45), and the other end is connected to the pipeline between the 4# valve (12) and the 2# pressure gauge (13); the separation circulation system is also provided with a bypass pipeline and a circulation pipeline; the bypass pipeline is led out from the pipeline between the 11# valve (48) and the separator (49), and is connected to the 17# valve ( 68), and 18# valve (69) are connected to the pipeline between 19# valve (70) and 13# valve (51); one end of the natural gas recovery tank (66) is connected to the pipeline between the separator (49) and 13# valve (51) through 12# valve (50), and the other end is connected to the pipeline between 1# valve (2) and compressor (3) through 16# valve (67); the circulation pipeline is led out from the liquid-solid boosting pipeline between 7# valve (28) and multiphase mixed transport pump (29), and connected to the pipeline between 19# valve (70) and 13# valve (51) after passing through 20# valve (71); The recovery unit is led out from the bottom of the separator (49) and connected to the inlet of the centrifugal solid-liquid separator (53) through the 14# valve (52); the liquid outlet at the top of the centrifugal solid-liquid separator (53) is connected to the liquid storage tank (55) through the 15# valve (54), and the solid outlet at the bottom is connected to the sulfur particle recovery tank (56); The particle tracing image velocimetry system comprises a water storage tank (22), a sulfur particle filling device (8), a first particle image velocimetry system and a second particle image velocimetry system; the water storage tank (22) is provided with liquid tracing particles, and the sulfur particle filling device (8) is provided with solid particle fluorescent tracing powder having a color different from that of the liquid tracing particles; the first particle image velocimetry system is connected in sequence to a 1# synchronous controller (58), a 1# laser transmitter (60) and a 1# optical lens (61) after being led out from a computer (57); a 1# high-definition camera (59) is connected to the top of the 1# synchronous controller (58); the second particle image velocimetry system is connected in sequence to a 2# synchronous controller (62), a 2# laser transmitter (64) and a 2# optical lens (65) after being led out from a computer (57); and a 2# high-definition camera (63) is connected to the top of the 2# synchronous controller (62).

2. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The pipeline of the natural gas filling system is equipped with a 2# gas flow meter (15), and the pipeline of the water filling system is equipped with a liquid flow meter (23). The pressure and ratio of the natural gas and water injected into the reaction kettle (16) can be controlled by controlling the compressor (3) and the water pump (24) respectively; at the same time, the temperature and pressure of the medium in the reaction kettle (16) and the mass transfer rate of the natural gas and water are adjusted by controlling the rotation speed of the stirrer (17) and the refrigeration power of the controllable temperature water bath (21) to generate natural gas hydrate.

3. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: Two colors of liquid tracer particles and solid fluorescent tracer powder are used to mark natural gas hydrate particles and sulfur particles. The first particle image velocimetry system and the second particle image velocimetry system can be used to observe the size morphology, migration trajectory, particle axial displacement velocity and deposition velocity of hydrate particles, sulfur particles and their agglomerates. The collision and rupture process of particle agglomerates and the migration law of hydrate and sulfur particles can be photographed.

4. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The sulfur particle filling system can increase the pressure in the sulfur particle filling device through the compressor (3) to make it higher than the pressure in the gas-liquid-solid phase distribution system pipeline downstream of the 3# valve (9) by 0.02 MPa, thereby forming a sulfur particle boosting pressure difference, and at the same time, the motor (10) drives the screw (11) to rotate and feed the material, so as to inject the sulfur particles in the sulfur particle filling device (8) into the gas-liquid-solid phase distribution system pipeline, thereby preventing the sulfur particles from adhering to and clogging the pipeline.

5. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The sulfur particle filling device (8) and the 3# valve (9) in the sulfur particle filling system are connected to the pipeline between the 4# temperature gauge (35) and the 1# hose (38) in a vertical direction to the ground. The sulfur particle filling device (8) is connected to the pipeline of the gas-liquid-solid phase distribution system by a vertical pipeline, which can reduce the adhesion of sulfur particles on the sulfur particle filling pipeline.

6. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The 1# transparent pipe section (40), the 2# transparent pipe section (42) and the U-shaped pipe section (43) are made of pressure-resistant transparent materials; the 1# throttle valve (39) and the 2# throttle valve (41) are electric regulating valves, which can accurately adjust the opening of the 1# throttle valve (39) and the 2# throttle valve (41) respectively, so that different pressure differences and flow rates are generated in the 1# transparent pipe section (40) and the 2# transparent pipe section (42).

7. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The gas in the hydrate preparation system flows out from the top pipeline of the reactor (16), and the liquid-solid mixture flows out from the lower outlet of the reactor (16). The two are combined in the pipeline between the 8# valve (30) and the 10# valve (33) to form a mixture composed of gas, liquid and solid phases. The sulfur particles in the sulfur particle filling system are mixed with the gas, liquid and solid phase mixture formed in the hydrate preparation system after passing through the 3# valve (9) and then enter the transparent test system composed of the 1# hose (38), the 1# throttle valve (39), the 1# transparent pipe section (40), the 2# throttle valve (41) and the 2# transparent pipe section (42), so that the migration law test of the gas, liquid and solid phase medium with two kinds of particles coexisting can be realized. One end of the rotating support frame (44) is vertically installed on the ground, and the other end is installed on the 1# transparent pipe section (40). The rotating support frame (44) can rotate at an acute angle with the ground plane within the range of 0°-45°, so that the migration law test of sulfur-containing natural gas hydrate in the inclined pipeline can be realized.

8. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: By changing the refrigeration power of the controllable temperature water bath (21) and the 1# circulating water bath control box (36), the degree of supercooling of the fluid in the reactor (16) is adjusted, so that the growth rate of the hydrate in the reactor (16) and the gas-liquid-solid phase distribution system pipeline can be controlled, thereby changing the hydrate volume concentration; by controlling the opening of the 3# valve (9) in the sulfur particle filling system, the filling amount of the sulfur particles is adjusted, thereby realizing the adjustment of the particle volume concentration in the transparent test system pipeline.

9. A device for testing the migration law of hydrates and sulfur particles in a throttling process pipeline according to claim 1, characterized in that: The gas-liquid-solid phase separation and transportation system comprises a gas booster pipeline and a liquid-solid booster pipeline. The migration law of natural gas hydrate dominated by water in the pipeline can be tested by fully opening the gas-liquid-solid phase separation and transportation system, or the migration law of water-containing natural gas hydrate dominated by natural gas in the pipeline can be tested by only opening the gas booster pipeline. By fully opening the gas-liquid-solid phase separation and transportation system pipeline or only opening the gas booster pipeline, flexible switching between the multiphase flow migration law test of hydrate particles dominated by water or natural gas in the pipeline can be achieved.

Images