Carbon dioxide injection system and injection process

Abstract

The application relates to a carbon dioxide injection system and injection process, belonging to the technical field of carbon dioxide transportation. The system comprises a carbon dioxide transportation pipeline (101) and a carbon dioxide pressurizing device (105). The air inlet of the carbon dioxide pressurizing device (105) is communicated with the carbon dioxide transportation pipeline (101), the air outlet of the carbon dioxide pressurizing device (105) is communicated with a carbon dioxide injection inlet (108), a carbon dioxide injection valve (107) is arranged between the air outlet of the carbon dioxide pressurizing device (105) and the carbon dioxide injection inlet (108), a heating mechanism is arranged on the carbon dioxide transportation pipeline (101), a first emptying pipeline (111) is further arranged between the carbon dioxide injection valve (107) and the carbon dioxide injection inlet (108), and an emptying valve is arranged on the first emptying pipeline (111). The heating mechanism is arranged on the carbon dioxide transportation pipeline, the carbon dioxide in the carbon dioxide transportation pipeline is heated first, dry ice is avoided, and normal transportation of the carbon dioxide is ensured.

Description

TECHNICAL FIELD

[0001] The application relates to a carbon dioxide injection system and injection process. BACKGROUND

[0002] With increasingly strict emission requirements, carbon dioxide as a major greenhouse gas is strictly limited in emission. In the past, part of carbon dioxide is injected into oil wells in the later stage of exploitation, and the pressure of the carbon dioxide is used to drive the carbon dioxide in the oil well to move to the wellhead, that is, carbon dioxide drives oil. However, in the past, the carbon dioxide generated in the production process of a chemical enterprise is first pressurized to be liquid, then the liquid carbon dioxide is transported to an oil field by using a tank truck, and then the carbon dioxide is sent into the oil well by using a pumping device.

[0003] Now, the oil well not only uses carbon dioxide to drive oil, but also becomes an excellent place for burying carbon dioxide. However, the cost of transporting carbon dioxide by using a tank truck is too high, which limits the burying of carbon dioxide. If gaseous carbon dioxide is directly transported to an oil field by using a pipeline, the cost will be greatly reduced. However, at present, there is no suitable equipment for transporting gaseous carbon dioxide. The main reason lies in that the physical properties of carbon dioxide are very complex, and the gaseous and liquid carbon dioxide are mixed, which is not conducive to transportation. SUMMARY

[0004] The application aims at overcoming the defects of the prior art, providing a carbon dioxide injection system and injection process, and achieving the transportation of gaseous and liquid carbon dioxide, stable transportation and reduction of the transportation cost of carbon dioxide.

[0005] The application adopts the technical scheme that the carbon dioxide injection system comprises a carbon dioxide conveying pipeline and a carbon dioxide pressurizing device, the gas inlet of the carbon dioxide pressurizing device is communicated with the carbon dioxide conveying pipeline, the gas outlet of the carbon dioxide pressurizing device is communicated with a carbon dioxide injection inlet, a carbon dioxide injection valve is arranged between the gas outlet of the carbon dioxide pressurizing device and the carbon dioxide injection inlet, a heating mechanism is arranged on the carbon dioxide conveying pipeline, a first emptying pipeline is further arranged between the carbon dioxide injection valve and the carbon dioxide injection inlet, and an emptying valve is arranged on the first emptying pipeline.

[0006] Preferably, a pressure sensor is connected to the carbon dioxide conveying pipeline between the heating mechanism and the carbon dioxide pressurizing device, and the pressure sensor is connected to a control cabinet.

[0007] Preferably, an integrated block is arranged on one side of the gas outlet of the carbon dioxide pressurizing device, the integrated block is connected with a temperature sensor and a pressure transmitter, the integrated block is connected with a safety emptying pipeline through a first safety valve, the carbon dioxide conveying pipeline on the inlet side of the heating mechanism is connected with the first emptying pipeline through a second emptying pipeline, and the second emptying pipeline and the safety emptying pipeline are connected through a second safety valve.

[0008] Preferably, the carbon dioxide pressurizing device comprises a pump head body, a feeding valve plate, a valve plate return spring, a piston and a cylinder sleeve, the pump head body is fixedly connected with the cylinder sleeve, the feeding valve plate and the piston are movably arranged in the cylinder sleeve, the pump head body is provided with a feeding port and a discharging port, a discharging check valve and a check valve return spring are arranged at the discharging port, a spring fixing hole is arranged on the pump head body, the valve plate return spring is arranged in the spring fixing hole, the valve plate return spring is arranged between the pump head body and the feeding valve plate, the valve plate return spring seals the feeding port, and a through hole is arranged on the feeding valve plate to connect the inner cavity of the cylinder sleeve and the check valve.

[0009] Preferably, the pump head body comprises a pump head shell, a valve seat pressing sleeve and a valve seat, the pump head shell is fixedly connected with the cylinder sleeve, the valve seat pressing sleeve and the valve seat are fixedly arranged in the pump head shell, the discharging port and the feeding port are arranged on the valve seat pressing sleeve, a plurality of feeding channels are arranged on the valve seat to communicate with the feeding port, and the spring fixing hole is arranged on the valve seat, the valve seat is arranged between the valve seat pressing sleeve and the feeding valve plate.

[0010] Preferably, a spring pull rod is arranged in the spring fixing hole, one end of the spring pull rod is fixedly connected with the feeding valve plate, the valve plate return spring is arranged outside the spring pull rod, a spring stop table is arranged on the spring fixing hole at the end of the spring pull rod away from the feeding valve plate, and the two ends of the valve plate return spring are fixedly connected with the spring stop table and the valve seat respectively.

[0011] Preferably, a cooling liquid hole is arranged on the cylinder sleeve, the piston is arranged between the feeding valve plate and the cooling liquid hole, a cooling cavity is arranged between the piston rod of the piston and the cylinder sleeve, and the cooling cavity is connected with a leakage detection device.

[0012] A carbon dioxide injection process using the above-mentioned carbon dioxide injection system, characterized by comprising the following steps:

[0013] 1) Before starting, first open the carbon dioxide injection valve to open the pipeline between the carbon dioxide pressurizing device and the carbon dioxide injection port, and open the emptying valve on the first emptying pipeline;

[0014] 2) Turn on the heating mechanism to heat the carbon dioxide in the carbon dioxide conveying pipeline, turn on the carbon dioxide pressurizing device, and start the carbon dioxide injection;

[0015] 3) After the injection is completed, first close the heating mechanism, close the carbon dioxide injection valve and the emptying valve, and return the carbon dioxide to the pipeline to ensure zero emission.

[0016] Preferably, in step 2), when the temperature sensor detects that the temperature reaches the temperature setting temperature, the air inlet valve on the inlet side of the carbon dioxide pressurizing device is opened.

[0017] Preferably, the pressure sensor is further arranged to detect the pressure in the carbon dioxide conveying pipeline in step 2), and the carbon dioxide pressurizing device is opened when the pressure in the carbon dioxide pressurizing device and the pipeline pressure are balanced.

[0018] Compared with the prior art, the above technical scheme of the carbon dioxide injection system has the beneficial effects that:

[0019] The heating mechanism is arranged on the carbon dioxide conveying pipeline, and the carbon dioxide in the carbon dioxide conveying pipeline is heated first to avoid the formation of dry ice and ensure the normal conveying of the carbon dioxide.

[0020] The pressure sensor is connected to the carbon dioxide conveying pipeline between the heating mechanism and the carbon dioxide pressurizing device, and the carbon dioxide pressurizing device is opened when the pressure in the carbon dioxide pressurizing device and the pressure in the carbon dioxide conveying pipeline are equal, so that the carbon dioxide pressurizing device can work normally and damage caused by high pressure can be avoided.

[0021] The feeding port and the discharging port of the carbon dioxide pressurizing device are arranged on the pump head body, the feeding port is sealed by the feeding valve plate, the feeding valve plate can be tightly attached to the pump head body in the piston discharging stroke, and the valve plate return spring is completely retracted into the spring fixing hole, so that there is no any extra gap in the whole pump cavity, the volumetric efficiency of the pump can be greatly improved to 99.9%, and the carbon dioxide injection system can not only convey gaseous carbon dioxide, but also convey carbon dioxide in a gas-liquid mixed state, so that the complex carbon dioxide conveying requirements can be met. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic view of the carbon dioxide injection system embodiment 1.

[0023] Figure 2 It is a schematic view of the carbon dioxide pressurizing device of embodiment 1.

[0024] Figure 3 It is Figure 2 It is an enlarged view of A in FIG.

[0025] Figure 4 It is Figure 2 It is a sectional view of B-B in FIG.

[0026] Figure 5 It is a front view of the sealing plug.

[0027] Figure 6 It is a schematic view of the carbon dioxide injection system embodiment 2.

[0028] Wherein: 1, pump head body 2, cylinder sleeve 3, piston 4, feed valve plate 5, pressure sleeve 6, valve seat 7, pump head shell 8, sealing plug 9, feed port 10, discharge port 11, cooling liquid hole 12, piston rod 13, packing seal assembly 14, valve plate reset spring 15, spring pull rod 16, first sealing platform 17, second sealing platform 18, discharge chute 19, feed channel 20, discharge groove 21, cooling cavity 22, spring fixing hole 23, discharge hole 101-carbon dioxide pipeline 102-vaporizer 103-conveying gate valve 104-pressure sensor 105-carbon dioxide booster 106-integrated block 107-carbon dioxide injection valve 108-carbon dioxide injection port 109-control cabinet 110-leak detection device 111-first exhaust line 112-first exhaust valve 113-second exhaust valve 114-safety valve 115-temperature sensor. DETAILED DESCRIPTION

[0029] Figures 1-5 The carbon dioxide injection system is the best embodiment, and the following will be described in detail with reference to the accompanying drawings Figures 1-6 Further illustrate the present application.

[0030] Example 1

[0031] Referring to Figure 1 The carbon dioxide injection system includes a carbon dioxide pipeline 101 and a carbon dioxide booster 105. The gas inlet of the carbon dioxide booster 105 is connected to the carbon dioxide pipeline 101. The carbon dioxide pipeline 101 is provided with a conveying gate valve 103. The gas outlet of the carbon dioxide booster 105 is connected to a carbon dioxide injection port 108. A carbon dioxide injection valve 107 is arranged between the gas outlet of the carbon dioxide booster 105 and the carbon dioxide injection port 108. A heating mechanism is arranged on the carbon dioxide pipeline 101. A first exhaust line 111 is arranged between the carbon dioxide injection valve 107 and the carbon dioxide injection port 108. The first exhaust line 111 is provided with a first exhaust valve 112.

[0032] The heating mechanism in this embodiment is a vaporizer 102. The vaporizer 102 heats the carbon dioxide in the carbon dioxide pipeline 101 to avoid the formation of dry ice and ensure the normal delivery of carbon dioxide. A pressure sensor 104 is connected to the carbon dioxide pipeline 101 between the vaporizer 102 and the carbon dioxide booster 105. The pressure sensor 104 is connected to a control cabinet 109. A temperature sensor 115 is arranged on the carbon dioxide pipeline 101 at the outlet side of the vaporizer 102.

[0033] The exhaust port side of the carbon dioxide pressurizing device 105 is provided with an integrated block 106, which is connected with a temperature sensor and a pressure transmitter, and is connected with a safety venting pipeline through a first safety valve 114. The carbon dioxide conveying pipeline 101 at the inlet side of the vaporizer 102 is connected with a second venting pipeline, which is provided with a second venting valve 113, and the integrated block 106 is further connected with a safety venting pipeline, and the second venting pipeline and the safety venting pipeline are connected through a second safety valve 114.

[0034] The carbon dioxide conveying pipeline 101 at the inlet side of the vaporizer 102 is further connected with a second venting pipeline, which is provided with a second venting valve 113, and the integrated block 106 is further connected with a safety venting pipeline, and the second venting pipeline and the safety venting pipeline are provided with a safety valve 114. In addition, the first venting pipeline 111 is connected through a third venting valve 116 at the outlet side of the integrated block 106, and the carbon dioxide injection inlet 108 is connected through a fourth venting valve 117 with the first venting pipeline 111.

[0035] Referring to Figures 2-5 The carbon dioxide injection system comprises a pump head body 1, a feed valve plate 4, a valve plate reset spring 14, a piston 3 and a cylinder sleeve 2. The pump head body 1 is fixed to one end of the cylinder sleeve 2, the other end of the cylinder sleeve 2 is provided with a packing seal assembly 13, the feed valve plate 4 and the piston 3 are movably arranged in the cylinder sleeve 2, the feed valve plate 4 is arranged on one side of the piston 3, the other side of the piston 3 is connected with a piston rod 12, one end of the piston rod 12 extending out of the cylinder sleeve 2 passes through the packing seal assembly 13 and is connected with a power mechanism, the pump head body 1 is provided with a feed inlet 9 and a discharge outlet 10, the discharge outlet 10 is provided with a discharge one-way valve, the pump head body 1 is provided with a spring fixing hole 22, the valve plate reset spring 14 is arranged in the spring fixing hole 22, the valve plate reset spring 14 is arranged between the pump head body 1 and the feed valve plate 4, the valve plate reset spring 14 seals the feed inlet 9, and the feed valve plate 4 is provided with a through hole communicating the inner cavity of the cylinder sleeve 2 with the discharge one-way valve.

[0036] For example, in the orientation of the drawing, when the piston rod 12 drives the piston 3 to move to the right, the pressure in the external carbon dioxide pipeline drives the spring pull rod 15 and the feed valve plate 4 to move to the right against the resistance of the valve plate reset spring 14, the piston 3 continues to move to the right, a pump cavity containing carbon dioxide is formed between the feed valve plate 4 and the piston 3, the carbon dioxide enters the pump cavity through the through hole in the feed valve plate 4, then the piston rod 12 drives the piston 3 to move to the left, the carbon dioxide in the pump cavity is compressed, at this time, the pressure in the pump cavity is greater than the pressure in the external carbon dioxide pipeline, so that the valve plate reset spring 14 drives the feed valve plate 4 to quickly move to the left, the feed inlet 9 is closed, the carbon dioxide in the pump cavity is discharged through the through hole in the feed valve plate 4, the discharge one-way valve and the discharge outlet 10, and one action cycle is completed.

[0037] The pump head body 1 comprises a pump head shell 7, a pressing sleeve 5 and a valve seat 6, the pump head shell 7 is fixedly connected with the cylinder sleeve 2, the pressing sleeve 5 and the valve seat 6 are fixed in the pump head shell 7, the pressing sleeve 5 and the pump head shell 7 are threadedly connected and sealed by a copper sealing gasket, the discharge port 10 and the feeding port 9 are both arranged on the pressing sleeve 5, one end of the pump head shell 7 is provided with a pipeline interface communicating with the discharge port 10 and the feeding port 9, the valve seat 6 is provided with a plurality of feeding channels 19 communicating with the feeding port 9, a plurality of spring fixing holes 22 are arranged on the valve seat 6, the spring fixing holes 22 are arranged alternately with the feeding channels 19, and the valve seat 6 is arranged between the pressing sleeve 5 and the feeding valve plate 4.

[0038] The spring fixing hole 22 is provided with a spring pull rod 15, one end of the spring pull rod 15 is fixedly connected with the feeding valve plate 4, the valve plate reset spring 14 is arranged on the outer side of the spring pull rod 15, and the other end of the spring pull rod 15 is provided with a spring stopper, and the two ends of the valve plate reset spring 14 are fixedly connected with the spring stopper and the valve seat 6 respectively.

[0039] The pressing sleeve 5 and the valve seat 6 are provided with a discharge chute 18 communicating with each other, the discharge one-way valve is a sealing plug 8 slidingly arranged in the discharge chute 18, a plurality of discharge grooves 20 are arranged on the side of the sealing plug 8, a discharge hole 23 communicating with the discharge chute 18 is arranged in the middle of the right end of the valve seat 6, the diameter of the discharge hole 23 is smaller than that of the discharge chute 18, and one end of the sealing plug 8 seals the discharge hole 23.

[0040] The feeding valve plate 4 is of an annular structure, the middle part of the feeding valve plate 4 is a through hole, the end of the piston 3 is provided with a first sealing table 16 inserted into the through hole, and the first sealing table 16 is further provided with a second sealing table 17 inserted into the discharge hole 23. The first sealing table 16 and the second sealing table 17 seal the through hole on the feeding valve plate 4 and the discharge hole 23 on the pressing sleeve 5 respectively, so as to prevent carbon dioxide from remaining in the through hole and the discharge hole 23, and thus the pump has a very high volumetric efficiency.

[0041] The first sealing table 16 and the second sealing table 17 of the embodiment are both conical tables, which are convenient for guiding and ensure that the first sealing table 16 is accurately inserted into the through hole and the second sealing table 17 is accurately inserted into the discharge hole 23. The through hole and the discharge hole 23 can be cylindrical holes or conical holes matched with each other, when the through hole and the discharge hole 23 are cylindrical holes, there will be a certain gap between the first sealing table 16 and the through hole and between the second sealing table 17 and the discharge hole 23, but the gap is small and will not greatly affect the volumetric efficiency of the pump.

[0042] The cylinder sleeve 2 is also provided with a cooling liquid hole 11, the piston 3 is arranged between the feed valve plate 4 and the cooling liquid hole 11, the piston rod 12 is in continuous contact with the packing seal assembly 13 in the continuous reciprocating operation, the piston rod 12 generates a large amount of heat, the cooling liquid hole 11 can be used to cool the piston rod 12, the pump cavity is formed between the piston 3 and the feed valve plate 4, and the cooling cavity 21 is formed between the other side of the piston 3 and the cylinder sleeve 2, and the cooling cavity 21 is connected with the leakage detection device 110. When the piston rod 12 moves to the left side, the cooling liquid is sucked into the cooling cavity 21, and when the piston rod 12 moves to the right side, the cooling liquid is discharged from the cooling cavity 21, without external power, the reciprocating movement of the piston rod 12 is used to realize the liquid inlet and liquid outlet of the cooling liquid, and the cooling liquid is usually water. The cooling liquid can cool and lubricate the piston rod 12 at the same time.

[0043] The cooling liquid outside the piston rod 12 in the cylinder sleeve 2 can cool the heat generated when the gaseous medium is compressed and lubricate the sealing ring and the packing seal assembly 13 of the piston rod 12, so that the lubrication, sealing and cooling effects of the piston are realized. The cooling and lubricating system is made into a full seal, the leakage detection device 110 detects the pressure in the cooling cavity 21, when the sealing ring of the piston 3 leaks, carbon dioxide will enter the cooling cavity 21, and the lubricating system will detect that the pressure increases, when the cooling liquid of the lubricating system leaks, the system will detect that the pressure decreases, and the system automatically alarms and stops for maintenance.

[0044] The working process of the carbon dioxide pressurizing device 105 includes an exhaust stroke and an intake stroke.

[0045] Intake stroke: when the piston rod 12 drives the piston 3 to move to the right side, the pressure in the external carbon dioxide pipeline makes the carbon dioxide push the spring pull rod 15 and the feed valve plate 4 to move to the right side against the resistance of the valve plate return spring 14, the piston 3 continues to move to the right side, a pump cavity containing carbon dioxide is formed between the feed valve plate 4 and the piston 3, the carbon dioxide enters the pump cavity through the feed port 9, the feed channel 19 and the through hole on the feed valve plate 4, at this time, the sealing plug 8 is pushed to the rightmost sealing discharge hole 23 by the spring (not shown in the figure), and the water in the cooling cavity 21 is discharged in the process that the piston rod 12 moves to the right side.

[0046] Exhaust stroke: the piston rod 12 drives the piston 3 to move to the left side, the carbon dioxide in the pump cavity is compressed, at this time, the pressure in the pump cavity is greater than the pressure in the external carbon dioxide pipeline, so that the valve plate return spring 14 drives the feed valve plate 4 to quickly move to the left side, the feed port 9 is closed, the carbon dioxide in the pump cavity pushes the sealing plug 8 to move to the left side, the carbon dioxide in the pump cavity is discharged from the discharge port 10 through the through hole on the feed valve plate 4, the discharge hole 23 and the discharge groove 20 on the side of the sealing plug 8, and the cooling water is sucked into the cooling cavity 21 in the process that the piston rod 12 moves to the left side.

[0047] The present application sets the feed port 9 and the discharge port 10 on the pump head body 1, and seals the feed port 9 by the feed valve plate 4, in the exhaust stroke of the piston 3, the feed valve plate 4 closely adheres to the valve seat 6, when the piston 3 strokes to the end, the piston 3 closely adheres to the valve seat 6 and the sealing plug 8 with a micro gap not more than 0.5mm, there is no any extra gap in the whole pump cavity, which can greatly improve the volumetric efficiency of the pump, and can reach 99.9%, and the carbon dioxide pump can not only transport gaseous carbon dioxide alone, but also transport carbon dioxide in gas-liquid mixed state, which meets the complex carbon dioxide transportation requirements.

[0048] The carbon dioxide injection process using the above carbon dioxide injection system, characterized in that it comprises the following steps:

[0049] 1. Before starting, first open the carbon dioxide injection valve 107, open the pipeline between the carbon dioxide pressurizing device 105 and the carbon dioxide injection port 108, and open the exhaust valve on the first exhaust pipeline 111.

[0050] 2. Open the vaporizer 102, heat the carbon dioxide in the carbon dioxide conveying pipeline 101 to 30-50℃, open the carbon dioxide pressurizing device 105, and start injecting carbon dioxide; when the temperature sensor 115 detects that the temperature reaches the set temperature, open the inlet valve of the carbon dioxide pressurizing device 105, and also detect the pressure in the carbon dioxide conveying pipeline 101 through the pressure sensor 104; when the pressure in the carbon dioxide pressurizing device 105 and the pipeline pressure are balanced, open the carbon dioxide pressurizing device 105.

[0051] 3. After the injection is completed, first close the vaporizer 102, close the carbon dioxide injection valve 107 and the first exhaust valve 112, and return the carbon dioxide to the pipeline to ensure zero emission.

[0052] When shutting down, first close the vaporizer 102, the carbon dioxide injection valve 107 and the first exhaust valve 112, and then sequentially open the second exhaust valve 113, the third exhaust valve 116 and the fourth exhaust valve 117 to return the carbon dioxide in the carbon dioxide pressurizing device 105 and the pump sled to the pipeline to ensure zero emission, and if the pressure is too high, the safety valve 114 is opened for protection.

[0053] When running, real-time safety monitoring is performed, when the pressure is too high, the pressure transmitter alarms and stops through PLC, if the pressure transmitter fails, the electric contact pressure gauge is directly connected to send an alarm and stop, if both the pressure transmitter and the electric contact pressure gauge fail, the safety valve connected to the integrated block 106 starts the protection system.

[0054] The runtime pressure sensor 104 senses the inlet pressure of the pipeline at any time, and automatically adjusts the rotation speed of the compressor according to the change of the pressure, and automatically reduces the rotation speed of the compressor when the inlet pressure is low to ensure that the gas supply amount matches the displacement of the compressor.

[0055] When the equipment is running, the cooling system is fully sealed, and the oil circulation air cooling system. If internal leakage occurs in the equipment, the pressure of the cooling system will increase, and if the cooling oil leaks, the pressure will decrease. The pressure transmitter sends a gas leakage and cooling liquid leakage signal according to the increase and decrease of the system pressure. If the instantaneous leakage is serious (the pressure increases and decreases within a few seconds), the emergency stop will be triggered.

[0056] When the first vent valve 112, the second vent valve 113, and the fourth vent valve 117 are closed, there is residual carbon dioxide in the pipeline, and the temperature changes, the pressure rises, and the safety valve 114 jumps to protect. The first vent valve 112 must be opened, and either the second vent valve 113 or the fourth vent valve 117 must be opened. The second vent valve 113 and the fourth vent valve 117 cannot be opened at the same time.

[0057] Example 2

[0058] Referring to Figure 6 In this embodiment, the first sealing station 16 and the second sealing station 17 are designed as cylindrical shapes, and the volumetric efficiency of the pump is higher.

[0059] The above description is only a preferred embodiment of the present application, and is not intended to limit the other forms of the present application. Any skilled person in the art can use the disclosed technical content to make changes or modifications to equivalent embodiments. However, any simple modification, equivalent change and modification made according to the technical essence of the present application without departing from the technical solution of the present application shall be within the protection scope of the present application.

Claims

1. A carbon dioxide injection system, characterized in that: It includes a carbon dioxide delivery pipeline (101) and a carbon dioxide booster device (105). The inlet of the carbon dioxide booster device (105) is connected to the carbon dioxide delivery pipeline (101), and the outlet of the carbon dioxide booster device (105) is connected to the carbon dioxide injection port (108). A carbon dioxide injection valve (107) is provided between the outlet of the carbon dioxide booster device (105) and the carbon dioxide injection port (108). A heating mechanism is provided on the carbon dioxide delivery pipeline (101). A first venting pipeline (111) is also provided between the carbon dioxide injection valve (107) and the carbon dioxide injection port (108). A venting valve is provided on the first venting pipeline (111). The carbon dioxide booster device (105) includes a pump head body (1), a feed valve plate (4), a valve plate return spring (14), a piston (3), and a cylinder liner (2). The pump head body (1) and the cylinder liner (2) are fixed relative to each other. The feed valve plate (4) and the piston (3) are movably arranged inside the cylinder liner (2). The pump head body (1) is provided with a feed port (9) and a discharge port (10). An exhaust check valve (8) and a check valve return spring are provided at the discharge port (10). The pump head body (1) is provided with a spring fixing hole (22). The valve plate return spring (14) is arranged inside the spring fixing hole (22). The valve plate return spring (14) is arranged between the pump head body (1) and the feed valve plate (4). The valve plate return spring (14) causes the feed valve plate (4) to seal the feed port (9). The feed valve plate (4) is provided with a through hole that connects the inner cavity of the cylinder liner (2) and the check valve.

2. The carbon dioxide injection system according to claim 1, characterized in that: A pressure sensor (104) is connected to the carbon dioxide delivery pipeline (101) between the heating mechanism and the carbon dioxide pressurization device (105), and the pressure sensor (104) is connected to the control cabinet (109).

3. The carbon dioxide injection system according to claim 1, characterized in that: The carbon dioxide booster device (105) has an integrated block (106) on one side of the exhaust port. The integrated block (106) is connected to a temperature sensor and a pressure transmitter. The integrated block (106) is connected to a safety venting pipeline through a first safety valve. The carbon dioxide delivery pipeline (101) on the inlet side of the heating mechanism is connected to the first venting pipeline (111) through a second venting pipeline. The second venting pipeline and the safety venting pipeline are connected through a second safety valve.

4. The carbon dioxide injection system according to claim 1, characterized in that: The pump head body (1) includes a pump head housing (7), a valve seat sleeve (5) and a valve seat (6). The pump head housing (7) is fixedly connected to the cylinder liner (2). The valve seat sleeve (5) and the valve seat (6) are fixed inside the pump head housing (7). The discharge port (10) and the feed port (9) are both opened on the valve seat sleeve (5). The valve seat (6) is provided with multiple feed channels (19) that connect to the feed port (9). The spring fixing hole (22) is opened on the valve seat (6). The valve seat (6) is located between the valve seat sleeve (5) and the feed valve plate (4).

5. The carbon dioxide injection system according to claim 4, characterized in that: A spring rod (15) is provided in the spring fixing hole (22). One end of the spring rod (15) is fixedly connected to the feed valve plate (4). The valve plate reset spring (14) is set on the outside of the spring rod (15). A spring stop is provided in the spring fixing hole (22) at the end of the spring rod (15) away from the feed valve plate (4). The two ends of the valve plate reset spring (14) are respectively fixed to the spring stop and the valve seat (6).

6. The carbon dioxide injection system according to claim 1, characterized in that: The cylinder liner (2) has a coolant hole (11), the piston (3) is located between the feed valve plate (4) and the coolant hole (11), and a cooling chamber (21) is provided between the piston rod (12) of the piston (3) and the cylinder liner (2). The cooling chamber (21) is connected to a leakage detection device.

7. A carbon dioxide injection process using the carbon dioxide injection system according to any one of claims 1 to 6, characterized in that: Includes the following steps: 1) Before starting the machine, first open the carbon dioxide injection valve (107) to open the pipeline between the carbon dioxide booster device (105) and the carbon dioxide injection port (108), and open the vent valve on the first vent pipeline (111). 2) Turn on the heating mechanism to heat the carbon dioxide in the carbon dioxide delivery pipe (101), turn on the carbon dioxide pressurization device (105) to start injecting carbon dioxide; 3) After injection is completed, first turn off the heating mechanism, then close the carbon dioxide injection valve (107) and the vent valve to return the carbon dioxide to the pipeline and ensure zero emissions.

8. The carbon dioxide injection process according to claim 7, characterized in that: In step 2), when the temperature sensor detects that the set temperature has been reached, the intake valve on the inlet side of the carbon dioxide booster device (105) is opened.

9. The carbon dioxide injection process according to claim 7, characterized in that: In step 2), the pressure in the carbon dioxide delivery pipeline (101) is also detected by the pressure sensor (104). When the pressure in the carbon dioxide booster device (105) is balanced with the pipeline pressure, the carbon dioxide booster device (105) is turned on.

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