A co2 gas-liquid miscible pipeline transportation system and method

Abstract

The present application belongs to the technical field of CCUS pipeline transportation, and discloses a CO2 gas-liquid mixed-phase pipeline transportation system and method.The system comprises a liquid CO2 transportation subsystem, a gaseous CO2 transportation subsystem and a mixed-phase pressurization transportation subsystem; the liquid CO2 transportation subsystem comprises a liquid CO2 unloading skid, a liquid CO2 storage tank and a liquid feeding pump connected in sequence; the gaseous CO2 transportation subsystem comprises a gaseous CO2 inlet manifold, a compressor, a dehydration device and a filter connected in sequence; the mixed-phase pressurization transportation subsystem comprises a static mixer, a high-pressure reciprocating mixed-transport pump, an outlet pressure stabilizer and a high-pressure pipeline connected in sequence; the liquid feeding pump is connected with the liquid inlet of the static mixer, and the filter is connected with the gas inlet of the static mixer.The present application can efficiently realize CO2 gas-liquid mixed-phase transportation, so that the CO2 can enter a transportation or injection pipeline after pressurization, the pressure reaches above the supercritical pressure, and the process is short, the energy consumption is low, and the efficiency and reliability are high.

Description

Technical Field

[0001] This invention belongs to the field of CCUS pipeline transportation technology, specifically relating to a CO2 gas-liquid mixed-phase pipeline transportation system and method. Background Technology

[0002] CO2 pipeline transportation is divided into three methods: gas phase transportation, liquid phase transportation, and supercritical state transportation. The gas phase transportation process involves high-concentration gaseous CO2 (typically 0.2 MPa, concentration ≥95%, room temperature) at low or normal pressure being pressurized to a certain pressure (≤4.5 MPa) by a compressor in a pipeline booster station before entering the gas phase CO2 pipeline and being transported to the pipeline endpoint. No insulation is required for this process. The liquid phase transportation process involves liquid CO2 (typically 2 MPa, concentration ≥99%, -20℃) being pressurized to a certain pressure by a liquid CO2 pump in a booster station before entering the liquid phase CO2 pipeline and being transported to the pipeline endpoint. This pipeline requires cooling. The supercritical state transportation process involves high-concentration gaseous CO2 (typically 0.2 MPa, concentration ≥95%, room temperature) at low or normal pressure being pressurized through multiple stages by a compressor in a booster station to a pressure above supercritical pressure (typically >9 MPa) before entering the supercritical CO2 pipeline and being transported to the pipeline endpoint. No insulation is required for this process. All three of the above transportation methods require that a single gaseous or liquid CO2 be pressurized by the booster equipment at the first station before entering the pipeline. Currently, there is no method for transporting CO2 in a mixed gas-liquid phase.

[0003] Currently, industrial gas-liquid mixing pumps include single screw pumps and twin screw pumps. However, screw pumps have disadvantages such as low compression ratio, low discharge pressure, low efficiency, short life of seals and vulnerable parts, and poor reliability. Summary of the Invention

[0004] This invention aims to address the technical problems existing in the prior art by providing a CO2 gas-liquid mixed-phase pipeline transportation system and method, which can efficiently realize the transportation of CO2 gas-liquid mixed phases, pressurize it and enter the transportation pipeline or injection pipeline, and the pressure reaches above the supercritical pressure. Moreover, the process flow is short, the operating energy consumption is low, and the system efficiency and reliability are high.

[0005] To achieve the above technical objectives, the present invention adopts the following technical solution:

[0006] A CO2 gas-liquid mixed-phase pipeline transportation system includes a liquid CO2 transportation subsystem, a gaseous CO2 transportation subsystem, and a mixed-phase pressurized transportation subsystem;

[0007] The liquid CO2 delivery subsystem includes a liquid CO2 unloading skid, a liquid CO2 storage tank, and a feeding pump connected in sequence.

[0008] The gaseous CO2 delivery subsystem includes a gaseous CO2 inlet manifold, a compressor, a dehydration device, and a filter connected in sequence.

[0009] The mixed-phase pressurized conveying subsystem includes a static mixer, a high-pressure reciprocating mixed conveying pump, an outlet pressure regulator, and a high-pressure pipeline connected in sequence.

[0010] The feed pump is connected to the liquid phase inlet of the static mixer via a pipeline, and the filter is connected to the gas phase inlet of the static mixer via a pipeline.

[0011] Furthermore, a first flow meter, a first thermometer, a first pressure gauge, and a first gate valve are installed on the connecting pipe between the feeding pump and the liquid phase inlet of the static mixer;

[0012] A second flow meter, a second thermometer, a second pressure gauge, and a second gate valve are installed on the connecting pipe between the filter and the gas phase inlet of the static mixer.

[0013] A third thermometer and a third pressure gauge are installed on the pipeline between the static mixer and the high-pressure reciprocating mixing pump.

[0014] The outlet pressure regulator is equipped with a fourth pressure gauge, and the outlet pipe of the outlet pressure regulator is equipped with a fourth thermometer.

[0015] Furthermore, the first flow meter is a mass flow meter or a venturi flow meter; the second flow meter is a vortex flow meter or a venturi flow meter.

[0016] Furthermore, the second flow meter, the second thermometer, the second pressure gauge, and the second gate valve are sequentially installed on the connecting pipe between the filter and the gas phase inlet of the static mixer along the gas delivery direction;

[0017] The gaseous CO2 inlet manifold also includes a secondary outlet, which is connected to the inlet pipe of the second flow meter via a bypass pipe; a third gate valve is installed on the bypass pipe.

[0018] Furthermore, when the pressure and moisture content of the incoming gaseous CO2 meet the inlet requirements of the static mixer, the third gate valve is opened to allow the incoming gaseous CO2 to be directly mixed with the liquid CO2 into the plunger-type mixing pump without the need for pressurization and dehydration.

[0019] Furthermore, it also includes instrument control systems;

[0020] The instrument control system is connected to each flow meter, thermometer and pressure gauge to adjust the operating parameters of each device in real time.

[0021] Meanwhile, the instrument control system is electrically connected to each gate valve to automatically control the opening and closing of each gate valve.

[0022] Furthermore, the inlet pressure of the compressor is the design low-pressure inlet pressure of the CO2 pipeline booster station, and the outlet pressure is the design output pressure of the dehydration device.

[0023] Furthermore, the compressor is a screw compressor or a reciprocating piston compressor.

[0024] Furthermore, the dehydration device is a molecular sieve dehydration device; the filter is a dust filtration device.

[0025] Furthermore, the inlet pressure of the high-pressure reciprocating mixed pump is the liquid CO2 storage pressure, and the outlet pressure is the pipeline design outlet pressure.

[0026] Furthermore, the high-pressure reciprocating mixed-transfer pump is equipped with over-temperature protection measures, specifically including:

[0027] Temperature sensors are installed on the compressed medium chamber and the transmission rod of the high-pressure reciprocating mixed-transfer pump. A temperature monitoring loop is set up in the mixed-transfer pump control system built into the high-pressure reciprocating mixed-transfer pump. The mixed-transfer pump control system receives the temperature data monitored by the temperature sensors and executes the following temperature protection measures:

[0028] When the temperature exceeds the rated operating temperature, the mixed pump control system will activate an alarm to remind manual adjustment of the liquid / gas phase ratio of the mixed pump feed to meet the liquid holdup requirements of the high-pressure reciprocating mixed pump.

[0029] When the temperature exceeds the upper limit of the operating temperature, the inlet valve of the high-pressure reciprocating mixed pump is forcibly closed by the mixed pump control system, and the operation is suspended.

[0030] Furthermore, the high-pressure reciprocating mixed pump is a plunger-type mixed pump.

[0031] Meanwhile, the present invention also provides a method for transporting CO2 gas-liquid mixed phases in a pipeline, implemented using the system described in any of the preceding claims, the method comprising the following steps:

[0032] When gaseous CO2 is input, the gaseous CO2 delivery subsystem and the liquid CO2 delivery subsystem are first opened. The liquid CO2 flows into the liquid CO2 storage tank through the liquid CO2 unloading skid for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank, it enters the feeding pump from the liquid CO2 storage tank for pressurization, and then enters the static mixer after metering.

[0033] Meanwhile, gaseous CO2 is collected through the inlet manifold and then enters the compressor for pressurization. The pressurized gaseous CO2 enters the dehydration device to remove moisture, then enters the filter to filter out the dust and impurities it carries, and then is metered and fed into the static mixer.

[0034] After being fully mixed in a static mixer, liquid CO2 and gaseous CO2 enter a high-pressure reciprocating mixing pump for pressurization. After pressurization, the pressure is stabilized by an outlet pressure stabilizer. When the pressure reaches the required outlet pressure, it enters a high-pressure pipeline for supercritical transport.

[0035] Furthermore, it also includes the following steps:

[0036] When gaseous CO2 is input, if the inlet gaseous CO2 pressure and moisture content meet the inlet requirements of the high-pressure reciprocating mixed-transfer pump (i.e., the gaseous CO2 pressure is equivalent to the liquid CO2 storage pressure, and the moisture content meets the pipeline input requirements), then the gaseous CO2 is directly metered after being collected in the gaseous CO2 inlet manifold and input into the static mixer. After the liquid CO2 and gaseous CO2 are fully mixed in the static mixer, they enter the high-pressure reciprocating mixed-transfer pump for pressurization, and finally enter the outlet pressure stabilizer to stabilize the pressure. When the pressure reaches the outlet pressure requirement, it enters the high-pressure pipeline for supercritical transport.

[0037] Furthermore, it also includes the following steps:

[0038] When there is no gaseous CO2 input, the gaseous CO2 delivery subsystem is shut down, and the liquid CO2 delivery subsystem is opened. Liquid CO2 flows into the liquid CO2 storage tank through the liquid CO2 unloading skid for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank, it enters the liquid CO2 storage tank and is pressurized by the feed pump. After metering, it is input into the static mixer. After flowing out of the static mixer, it enters the high-pressure reciprocating mixing pump and is pressurized to above the supercritical pressure. Then, it enters the outlet pressure stabilizer to stabilize the pressure and finally enters the high-pressure pipeline for supercritical delivery.

[0039] Compared with the prior art, the beneficial effects of the present invention are:

[0040] (1) The high-pressure reciprocating mixed pump is a positive displacement pump that uses the reciprocating motion of a piston or plunger in the pump cylinder to transport liquid. Compared with the screw pump, the high-pressure reciprocating mixed pump has the functions of both a pump and a compressor, has an internal compression function, is highly efficient and energy-saving, and can adapt to complex gas-liquid mixed transport conditions with high gas content and high compression ratio. The CO2 gas-liquid mixed pipeline transport system and method provided by the present invention mixes the transported liquid CO2 with the gaseous CO2 that has been pressurized and dehydrated in the pipeline. The plunger mixed pump simultaneously pressurizes the gaseous and liquid CO2 media to above the supercritical pressure and then enters the pipeline for transport. Compared with the process of separately setting up a compressor and a screw pump to pressurize the gaseous and liquid CO2 to above the supercritical pressure and then mixing them into the pipeline for transport, the station process flow is greatly reduced and the number of equipment is reduced. Not only is the engineering investment lower, but the mixed pump also has a shorter process flow, lower operating energy consumption, and higher system efficiency and reliability compared with the combination of compressor and screw pump.

[0041] (2) The CO2 gas-liquid mixed-phase pipeline transportation system and method provided by the present invention applies the plunger-type mixed-transport pump to the field of CO2 pipeline transportation. Since the temperature of liquid CO2 is low, it is mixed with gaseous CO2 and then pressurized and transported by the plunger-type mixed-transport pump. Compared with the pressurization by the compressor, the outlet medium temperature will not be too high, thus reducing the energy consumption of cooling equipment such as air coolers and significantly reducing operating costs.

[0042] (3) The CO2 gas-liquid mixed-phase pipeline transportation system and method provided by the present invention can be applied to the first station of the long-distance carbon dioxide pipeline pressurization, or to scenarios such as when injecting carbon dioxide in oil fields, where the injected medium is purchased liquid carbon dioxide and extracted gaseous carbon dioxide that need to be pressurized at the same time. The process has significant economic benefits, strong practicality, and high application and promotion value. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the CO2 gas-liquid mixed-phase pipeline transportation system according to an embodiment of the present invention. Detailed Implementation

[0044] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0046] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0047] Example 1

[0048] Combination Figure 1 As shown, this embodiment of the invention provides a CO2 gas-liquid mixed-phase pipeline transportation system, including a liquid CO2 unloading skid 1, a liquid CO2 storage tank 2, a feeding pump 3, a gaseous CO2 inlet manifold 4, a compressor 5, a dehydration device 6, a filter 7, a static mixer 8, a plunger-type mixed-transport pump 9, an outlet pressure regulator 10, a high-pressure pipeline 11, a first gate valve 22, a second gate valve 33, a third gate valve 44, a first flow meter 101, a second flow meter 102, a first pressure gauge 201, a second pressure gauge 202, a third pressure gauge 203, a fourth pressure gauge 204, a first thermometer 301, a second thermometer 302, a third thermometer 303, and a fourth thermometer 304.

[0049] The liquid CO2 unloading skid 1 is connected to the inlet of the liquid CO2 storage tank 2 via a pipeline. The outlet of the liquid CO2 storage tank 2 is connected to the inlet of the feeding pump 3 via a pipeline. The outlet of the feeding pump 3 is connected to the liquid phase inlet of the static mixer 8 via a pipeline. The outlet of the gaseous CO2 inlet manifold 4 is connected to the inlet of the compressor 5 via a pipeline. The outlet of the compressor 5 is connected to the inlet of the dehydration device 6 via a pipeline. The outlet of the dehydration device 6 is connected to the inlet of the filter 7 via a pipeline. The outlet of the filter 7 is connected to the gas phase inlet of the static mixer 8 via a pipeline. The outlet of the static mixer 8 is connected to the inlet of the plunger-type mixing pump 9 via a pipeline. The outlet of the plunger-type mixing pump 9 is connected to the inlet of the outlet pressure regulator 10 via a pipeline. The outlet of the outlet pressure regulator 10 is connected to the inlet of the high-pressure pipeline 11 via a pipeline. The secondary outlet of the gaseous CO2 inlet manifold 4 is connected to the gas phase inlet of the static mixer 8 via a pipeline.

[0050] The connecting pipe between the liquid feed pump 3 and the liquid phase inlet of the static mixer 8 is sequentially equipped with a first flow meter 101, a first thermometer 301, a first pressure gauge 201 and a first gate valve 22.

[0051] The connecting pipe between the filter 7 and the gas phase inlet of the static mixer 8 is equipped with a second flow meter 102, a second thermometer 302, a second pressure gauge 202, and a second gate valve 33; the gaseous CO2 inlet manifold 4 also includes a secondary outlet, which is connected to the inlet pipe of the second flow meter 102 via a bypass pipe; a third gate valve 44 is provided on the bypass pipe.

[0052] A third thermometer 303 and a third pressure gauge 203 are installed on the pipeline between the static mixer 8 and the high-pressure reciprocating mixing pump 9; a fourth pressure gauge 204 is connected to the outlet pressure regulator 10, and a fourth thermometer 304 is installed on the connecting pipeline between the outlet pressure regulator 10 and the high-pressure pipeline 11.

[0053] The first flow meter 101 is installed on the pipeline between the feed pump 3 and the static mixer 8 to measure the amount of liquid CO2 gas entering the plunger-type mixing pump 9.

[0054] The second flow meter 102 is installed on the pipeline between the filter 7 and the static mixer 8 to measure the amount of gaseous CO2 entering the plunger-type mixing pump 9;

[0055] The first flow meter 101 is a mass flow meter, a venturi flow meter, etc.; the second flow meter 102 is a vortex flow meter, a venturi flow meter, etc.

[0056] The feeding pump 3 is installed on the pipeline between the liquid CO2 storage tank 2 and the liquid phase inlet of the static mixer 8. The feeding pump 3 is a shielded pump.

[0057] Compressor 5 can pressurize gaseous CO2. Compressor 5 is generally a screw or reciprocating piston compressor. The inlet pressure is the design low-pressure inlet pressure of the CO2 pipeline booster station, and the outlet pressure is the design output pressure of the dehydration device.

[0058] The dehydration device 6 is a molecular sieve dehydration device, which removes moisture from the incoming gaseous CO2, lowers the water dew point, and avoids corrosion of downstream pipelines and equipment.

[0059] The filter 7 is a dust filtration device that removes dust carried in the gaseous CO2 that has passed through the molecular sieve dehydration device.

[0060] The inlet pressure of the plunger-type mixed-transfer pump 9 is the liquid CO2 storage pressure, and the outlet pressure is the pipeline design outlet pressure.

[0061] The plunger-type mixing pump 9 cannot pressurize pure gaseous CO2 for extended periods, otherwise it will cause overheating and damage to the equipment. Therefore, the plunger-type mixing pump is equipped with over-temperature protection measures, specifically including:

[0062] Temperature sensors are installed on the compression medium chamber and the transmission rod of the plunger-type mixing pump 9. A temperature monitoring loop is set in the mixing pump control system of the plunger-type mixing pump 9. The mixing pump control system receives the temperature data monitored by the temperature sensors and performs the following temperature protection measures:

[0063] When the temperature exceeds the rated operating temperature of 130℃, the control system of the mixed pump will activate an alarm to remind manual adjustment of the ratio of liquid phase / gas phase in the feed of the mixed pump to meet the liquid holdup requirements of the plunger-type mixed pump 9.

[0064] When the temperature exceeds the upper limit of the operating temperature of 160°C, the inlet valve of the high-pressure reciprocating mixed pump is forcibly closed by the mixed pump control system, and the operation is suspended.

[0065] Analysis revealed that the main causes of high temperatures in the mixed-transfer pump are idling or insufficient liquid holdup (different types of mixed-transfer pumps have different liquid holdup requirements). When the ratio of liquid to gas phase in the pump's feed exceeds a certain value, the heat generated during compression increases, and insufficient heat dissipation from the contact liquid phase and the pump itself leads to higher temperatures. Therefore, when the temperature exceeds the pump's operating temperature, the liquid to gas phase ratio must be strictly controlled to meet the pump's liquid holdup requirements.

[0066] When the temperature exceeds the upper limit of the operating temperature, the inlet valve of the plunger-type mixing pump 9 shall be forcibly closed, and the operation shall be suspended. The pump shall be restarted when the temperature returns to below the rated operating temperature. If the shutdown time is long, the equipment, container and pipeline shall be vented and depressurized before restarting.

[0067] The power equipment, including the feeding pump 3, compressor 5, and plunger-type mixed transfer pump 9, are all driven by electric motors.

[0068] The CO2 gas-liquid mixed-phase pipeline transportation system also includes an instrument control system; the instrument control system is connected to each flow meter, thermometer and pressure gauge for real-time adjustment of the operating parameters of each device; at the same time, the instrument control system is electrically connected to each gate valve for automatic control of the opening and closing of each gate valve.

[0069] Example 2

[0070] This invention provides a method for transporting CO2 gas-liquid mixed phases via pipeline, implemented using the system described in Example 1. The method includes the following steps:

[0071] When gaseous CO2 is input, the first gate valve 22 and the second gate valve 33 are opened first, and the third gate valve 44 is closed. Liquid CO2 flows from the tanker truck into the liquid CO2 storage tank 2 in the station through the liquid CO2 unloading skid 1 for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank 2, the feeding pump 3 is turned on. After being measured by the first flow meter 101, the liquid CO2 is input into the static mixer 8. At the same time, low-pressure gaseous CO2 is collected through the inlet manifold 4 and enters the compressor 5 for pressurization. The pressurized gaseous CO2 enters the dehydration device 6 to remove most of the water, and then enters the filter 7 to filter out the dust and impurities it carries. After being measured by the second flow meter 102, it is input into the static mixer 8. After the liquid CO2 and gaseous CO2 are fully mixed in the static mixer 8, they enter the plunger-type mixing pump 9 for pressurization. Finally, they enter the outlet pressure stabilizer 10 to stabilize the pressure. When the pressure reaches the outlet pressure requirement, they enter the high-pressure pipeline 11 for supercritical transport.

[0072] If the inlet gaseous CO2 pressure and moisture content meet the inlet requirements of the plunger-type mixed-transfer pump 9, that is, the gaseous CO2 pressure is equivalent to the liquid CO2 storage pressure, and the moisture content meets the pipeline input index requirements, then the third gate valve 44 is opened and the compressor 5 inlet is closed. This allows the gaseous CO2 to be collected in the gaseous CO2 inlet manifold 4, measured by the second flow meter 102, and then input into the static mixer 8. After the liquid CO2 and gaseous CO2 are fully mixed in the static mixer 8, they enter the plunger-type mixed-transfer pump 9 for pressurization. Finally, they enter the outlet pressure stabilizer 10 to stabilize the pressure. When the pressure reaches the outlet pressure requirement, they enter the high-pressure pipeline 11 for supercritical transport.

[0073] In addition, if there is no gaseous CO2 input, the second gate valve 33 is closed and the first gate valve 22 is opened. Liquid CO2 flows from the tanker truck into the liquid CO2 storage tank 2 in the station through the liquid CO2 unloading skid 1 for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank 2, it enters the feeding pump 3 from the bottom outlet of the liquid CO2 storage tank 2 for pressurization. Then, after being measured by the first flow meter 101, it is input into the static mixer 8. After flowing out of the static mixer 8, it enters the plunger-type mixing pump 9 for pressurization to above the supercritical pressure. Then, it enters the outlet pressure stabilizer 10 to stabilize the pressure. Finally, it enters the high-pressure pipeline 11 for supercritical transport.

[0074] In this embodiment of the invention, liquid CO2 transported from the warehouse is mixed with gaseous CO2 that has been pressurized and dehydrated from the pipeline. A plunger-type mixing pump 9 is used to simultaneously pressurize the gaseous and liquid CO2 media to above supercritical pressure before they enter the high-pressure pipeline 11 for transportation. Compared with the process of separately setting up compressors and pumps to pressurize the gaseous and liquid CO2 to above supercritical pressure before mixing and transportation through pipelines, this greatly reduces the station process flow and the number of equipment. Not only is the engineering investment lower, but the mixing pump also has lower energy consumption and higher system efficiency and reliability compared with the combination of compressor and screw pump.

[0075] The above description is merely an embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the scope of the present invention should be included within the protection scope of the present invention.

Claims

1. A CO2 gas-liquid mixed-phase pipeline transportation system, characterized in that, It includes a liquid CO2 transport subsystem, a gaseous CO2 transport subsystem, and a mixed-phase pressurized transport subsystem; The liquid CO2 delivery subsystem includes a liquid CO2 unloading skid, a liquid CO2 storage tank, and a feeding pump connected in sequence. The gaseous CO2 delivery subsystem includes a gaseous CO2 inlet manifold, a compressor, a dehydration device, and a filter connected in sequence. The mixed-phase pressurized conveying subsystem includes a static mixer, a high-pressure reciprocating mixed conveying pump, an outlet pressure regulator, and a high-pressure pipeline connected in sequence. The feed pump is connected to the liquid phase inlet of the static mixer via a pipeline, and the filter is connected to the gas phase inlet of the static mixer via a pipeline; The connecting pipe between the feeding pump and the liquid phase inlet of the static mixer is equipped with a first flow meter, a first thermometer, a first pressure gauge and a first gate valve; A second flow meter, a second thermometer, a second pressure gauge, and a second gate valve are installed on the connecting pipe between the filter and the gas phase inlet of the static mixer. A third thermometer and a third pressure gauge are installed on the pipeline between the static mixer and the high-pressure reciprocating mixing pump. The outlet pressure regulator is equipped with a fourth pressure gauge, and the outlet pipe of the outlet pressure regulator is equipped with a fourth thermometer. The second flow meter, the second thermometer, the second pressure gauge, and the second gate valve are sequentially installed on the connecting pipe between the filter and the gas phase inlet of the static mixer along the gas delivery direction; The gaseous CO2 inlet manifold also includes a secondary outlet, which is connected to the inlet pipe of the second flow meter via a bypass pipe; a third gate valve is installed on the bypass pipe.

2. The system according to claim 1, characterized in that, The first flow meter is a mass flow meter or a venturi flow meter; the second flow meter is a vortex flow meter or a venturi flow meter.

3. The system according to claim 1, characterized in that, When the pressure and moisture content of the incoming gaseous CO2 meet the inlet requirements of the static mixer, the third gate valve is opened to allow the incoming gaseous CO2 to be directly mixed with the liquid CO2 into the plunger-type mixing pump without the need for pressurization and dehydration.

4. The system according to claim 1, characterized in that, It also includes the instrument control system; The instrument control system is connected to each flow meter, thermometer and pressure gauge to adjust the operating parameters of each device in real time. Meanwhile, the instrument control system is electrically connected to each gate valve to automatically control the opening and closing of each gate valve.

5. The system according to claim 1, characterized in that, The compressor's inlet pressure is the design low-pressure inlet pressure of the CO2 pipeline booster station, and its outlet pressure is the design output pressure of the dehydration device.

6. The system according to claim 4, characterized in that, The compressor is a screw compressor or a reciprocating piston compressor.

7. The system according to claim 1, characterized in that, The dehydration device is a molecular sieve dehydration device; the filter is a dust filtration device.

8. The system according to claim 1, characterized in that, The inlet pressure of the high-pressure reciprocating mixed pump is the liquid CO2 storage pressure, and the outlet pressure is the pipeline design outlet pressure.

9. The system according to claim 1, characterized in that, The high-pressure reciprocating mixed pump is equipped with over-temperature protection measures, specifically including: Temperature sensors are installed on the compressed medium chamber and the transmission rod of the high-pressure reciprocating mixed-transfer pump. A temperature monitoring loop is set up in the mixed-transfer pump control system built into the high-pressure reciprocating mixed-transfer pump. The mixed-transfer pump control system receives the temperature data monitored by the temperature sensors and executes the following temperature protection measures: When the temperature exceeds the rated operating temperature, the mixed pump control system will activate an alarm to remind manual adjustment of the liquid / gas phase ratio of the mixed pump feed to meet the liquid holdup requirements of the high-pressure reciprocating mixed pump. When the temperature exceeds the upper limit of the operating temperature, the inlet valve of the high-pressure reciprocating mixed pump is forcibly closed by the mixed pump control system, and the operation is suspended.

10. The system according to any one of claims 1-9, characterized in that, The high-pressure reciprocating mixed pump is a plunger-type mixed pump.

11. A method for transporting CO2 gas-liquid mixed phases via pipeline, implemented using the system described in any one of claims 1-10, characterized in that, The method includes the following steps: When gaseous CO2 is input, the gaseous CO2 delivery subsystem and the liquid CO2 delivery subsystem are first opened. The liquid CO2 flows into the liquid CO2 storage tank through the liquid CO2 unloading skid for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank, it enters the feeding pump from the liquid CO2 storage tank for pressurization, and then enters the static mixer after metering. Meanwhile, gaseous CO2 is collected through the inlet manifold and then enters the compressor for pressurization. The pressurized gaseous CO2 enters the dehydration device to remove moisture, then enters the filter to filter out the dust and impurities it carries, and then is metered and fed into the static mixer. After being fully mixed in a static mixer, liquid CO2 and gaseous CO2 enter a high-pressure reciprocating mixing pump for pressurization. After pressurization, the pressure is stabilized by an outlet pressure stabilizer. When the pressure reaches the required outlet pressure, it enters a high-pressure pipeline for supercritical transport.

12. The method according to claim 11, characterized in that, It also includes the following steps: When gaseous CO2 is input, if the inlet gaseous CO2 pressure and moisture content meet the inlet requirements of the high-pressure reciprocating mixed-transfer pump (i.e., the gaseous CO2 pressure is equivalent to the liquid CO2 storage pressure, and the moisture content meets the pipeline input requirements), then the gaseous CO2 is directly metered after being collected in the gaseous CO2 inlet manifold and input into the static mixer. After the liquid CO2 and gaseous CO2 are fully mixed in the static mixer, they enter the high-pressure reciprocating mixed-transfer pump for pressurization, and finally enter the outlet pressure stabilizer to stabilize the pressure. When the pressure reaches the outlet pressure requirement, it enters the high-pressure pipeline for supercritical transport.

13. The method according to claim 11, characterized in that, It also includes the following steps: When there is no gaseous CO2 input, the gaseous CO2 delivery subsystem is shut down, and the liquid CO2 delivery subsystem is opened. Liquid CO2 flows into the liquid CO2 storage tank through the liquid CO2 unloading skid for storage. When there is sufficient liquid CO2 in the liquid CO2 storage tank, it enters the liquid CO2 storage tank and is pressurized by the feed pump. After metering, it is input into the static mixer. After flowing out of the static mixer, it enters the high-pressure reciprocating mixing pump and is pressurized to above the supercritical pressure. Then, it enters the outlet pressure stabilizer to stabilize the pressure and finally enters the high-pressure pipeline for supercritical delivery.

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