Carbon dioxide gasification and pressurization device and method

Abstract

The present invention provides a carbon dioxide gasification and pressurization device and method, the device comprising a buffer tank and a pressurization pipeline, the buffer tank being connected to the pressurization pipeline, the pressurization pipeline being provided with a filter, a shielded pump, a flow meter, a screw pump, a vaporizer, and a discharge interface in sequence, the discharge interface being located at one end of the pressurization pipeline away from the buffer tank. The carbon dioxide gasification and pressurization device of the present invention can complete the steps of pressurization, cooling, self-pressurization, pressurization, gasification, temperature adjustment, and pressure adjustment; liquid carbon dioxide is pressurized and then gasified, and the output gaseous carbon dioxide can maintain a certain pressure and temperature; the output gaseous carbon dioxide temperature and pressure can be adjusted according to construction requirements to achieve continuous and stable output of gaseous carbon dioxide.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas field development, and in particular relates to a carbon dioxide gasification and pressurization device and method. Background Art

[0002] In the production increase and development of low permeability oil and gas reservoirs, carbon dioxide fracturing technology, as a new waterless fracturing technology, uses anhydrous liquid carbon dioxide as the fracturing medium. It has the advantages of low damage, easy backflow, easy fracture creation, and environmental protection. It is particularly suitable for low-pressure, low-permeability, dense and water-sensitive complex rock formations. It has a good effect on the transformation of reservoirs with severe oil and gas pollution and low water content, and can significantly increase the production of single wells.

[0003] In the application of CO2 fracturing technology, due to the critical state of CO2, the suction of the fracturing truck and the friction of the pipeline during the construction process cause the liquid CO2 in the surface liquid supply pipeline to partially vaporize. This causes the fracturing truck to run out of pumps, making it difficult to increase the construction displacement and extremely unstable liquid supply. If CO2 dry fracturing is performed with sand, the sand ratio cannot be further increased, the sand addition capacity is limited, and it is easy to cause sand blockage, affecting the post-fracturing effect. The current nitrogen booster device can solve this problem, but the high construction cost of nitrogen boosting, including liquid nitrogen, liquid nitrogen pump trucks, and nitrogen booster devices, further increases the cost of CO2 dry fracturing, which is not conducive to the promotion and application of this technology. Summary of the Invention

[0004] To address the above issues, the present invention provides a carbon dioxide gasification and pressurization device and method. To achieve the above objectives, the following technical solutions are adopted:

[0005] A carbon dioxide gasification and boosting device includes a buffer tank and a boosting pipeline. The buffer tank is connected to the boosting pipeline. The boosting pipeline is sequentially provided with a filter, a shielded pump, a flow meter, a screw pump, a gasifier and a discharge interface. The discharge interface is located at the end of the boosting pipeline away from the buffer tank.

[0006] Preferably, the boost pipeline is further provided with a main outlet manual valve, a first safety valve, a first pressure relief valve, a bellows, a second safety valve, a pump outlet manual valve, a second pressure sensor, a pump outlet check valve, a pump outlet discharge valve, a vaporizer outlet electric valve, a second pressure relief valve, a first temperature sensor, a third pressure sensor, a main line electric switch valve, a pump cooling drain valve, a main outlet check valve, a third temperature sensor, a discharge outlet manual valve, a third pressure relief valve, a fourth safety valve, a third safety valve and an electric drain valve; wherein, the main outlet manual valve, the first safety valve, the first pressure relief valve, the filter, the bellows Pipe, shielded pump, flow meter, screw pump, second safety valve, pump outlet manual valve, second pressure sensor, pump outlet one-way valve, pump body cooling drain valve, pump outlet liquid discharge valve, vaporizer, vaporizer outlet electric valve, second pressure relief valve, first temperature sensor, third pressure sensor, main line electric switch valve, main line outlet one-way valve, third temperature sensor, discharge outlet manual valve, third pressure relief valve and discharge interface are arranged in sequence, the second pressure relief valve and the fourth safety valve are arranged in parallel, the third pressure relief valve and the third safety valve are arranged in parallel, and the third pressure sensor and the electric drain valve are arranged in parallel.

[0007] Preferably, it also includes a charging pipeline, a 1# main pipeline and a 2# main pipeline respectively connected to the buffer tank, and the charging pipeline is provided with a charging interface, a charging switch valve and a first buffer tank liquid inlet switch valve in sequence, and the charging interface is located at the end of the charging pipeline away from the buffer tank; one end of the 1# main pipeline and the 2# main pipeline is respectively connected to the buffer tank, and the other end is respectively connected to the front and rear ends of the screw pump, the 1# main pipeline is provided with a 1# main pipeline charging valve, and the 2# main pipeline is provided with a 2# main pipeline charging valve.

[0008] Preferably, it also includes a liquid filling pipeline connected to the buffer tank, and the liquid filling pipeline is provided with a liquid filling interface, a liquid filling switch valve and a second buffer tank liquid inlet switch valve in sequence. The liquid filling interface is located at the end of the liquid filling pipeline away from the buffer tank, and the buffer tank is provided with an exhaust electric valve.

[0009] Preferably, it further comprises a self-pressurizing pipeline, which is provided with an evaporator liquid inlet switch valve, an evaporator and an evaporator one-way valve in sequence from bottom to top, and both ends of the self-pressurizing pipeline are connected to the buffer tank.

[0010] Preferably, it also includes a return pipeline, one end of which is connected to the buffer tank, and the other end is connected to the boost pipeline and is arranged at the outlet end of the gasifier; a cooling electric valve and a return pipeline one-way valve are sequentially provided on the return pipeline, and the return pipeline one-way valve is located at one end of the return pipeline close to the buffer tank.

[0011] A carbon dioxide gasification and pressurization method comprises the following steps: pressurization, cooling, gasification and pressure relief.

[0012] Preferably, the pressurization is specifically as follows: closing the main line electric switch valve, opening the 1# main line pressure charging valve, 2# main line pressure charging valve, pump inlet manual valve, pump outlet manual valve, cooling electric valve and pressure switching valve in sequence, and pressurizing the buffer tank and the screw pump inlet and outlet pipelines. When the buffer tank pressure reaches the preset value, the pressurization is completed.

[0013] Preferably, the cooling includes: liquid inlet to the buffer tank, self-pressurization of the buffer tank and a cold pump,

[0014] Preferably, the buffer tank is filled with liquid by opening the filling switch valve, adjusting the exhaust electric valve within the range of 30%-40%, exhausting the liquid while filling the buffer tank, and closing the exhaust electric valve and the filling switch valve in sequence when the liquid level reaches the preset level;

[0015] The buffer tank self-pressurization is specifically as follows: the evaporator liquid inlet switch valve is opened, and the liquid carbon dioxide in the buffer tank flows into the evaporator by its own weight, and is gasified by the evaporator and then sent into the buffer tank, thereby pressurizing the buffer tank;

[0016] The specific steps of the cold pump are: open the cooling electric valve, electric temperature regulating valve, and vaporizer outlet electric valve in sequence, open the pump body cooling drain valve to the specified value, start the shielded pump first, then start the screw pump, observe the pump body cooling drain valve outlet, and when dry ice appears, close the pump body cooling drain valve, establish an internal cycle for cooling, and complete the cold pumping.

[0017] Preferably, the gasification includes: a gasification preparation stage, a pressurization stage and a pause stage.

[0018] The gasification preparation stage specifically includes: opening the liquid filling switch valve, opening the electric drain valve and the gasifier outlet electric valve, starting the gasifier, and running the screw pump. When the first temperature sensor indicates a value between T1 and T2 and the pressure sensor indicates a value between P1 and P2, the gasification preparation stage is completed;

[0019] The pressurization stage specifically includes: opening the main line electric switch valve, closing the electric drain valve, increasing the operating power of the shielded pump and the screw pump according to site requirements, increasing the pressure of the carbon dioxide, and starting pressurization. During the pressurization process, the reading of the third pressure sensor is ensured to be within the range of P1′-P2′ and the reading of the third temperature sensor is within the range of T1-T2;

[0020] The pause stage is specifically as follows: when a short standby is required during the construction process, the operating steps are: first open the electric drain valve, then close the main line electric switch valve, reduce the operating power of the shielded pump and the screw pump, and be in a standby state; the long standby operation steps are: first open the cooling electric valve, stop the gasifier, then close the gasifier outlet electric valve and the electric temperature control valve, reduce the operating power of the shielded pump and the screw pump, and the device is in an internal circulation state.

[0021] Preferably, the pressure relief is specifically as follows: close the screw pump, shielded pump, vaporizer, main line electric switch valve, and liquid filling switch valve in sequence, open the pressure charging switch valve, open the electric drain valve to drain the liquid, and when there is no dry ice at the outlet of the electric drain valve, it means that the liquid phase is discharged. Close the pressure charging switch valve, open the exhaust electric valve to discharge the pipeline pressure to zero.

[0022] The present invention has the following beneficial effects: (1) the carbon dioxide gasification and pressurization device of the present invention can complete the steps of pressurization, cooling, self-pressurization, pressurization, gasification, temperature regulation and pressure regulation; (2) the present invention pressurizes liquid carbon dioxide and then gasifies it, and the output gaseous carbon dioxide can maintain a certain pressure and temperature; (3) the temperature and pressure of the output gaseous carbon dioxide of the present invention can be adjusted according to construction requirements, so as to achieve continuous and stable output of gaseous carbon dioxide.

[0023] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 The figure shows the structural schematic diagram of the carbon dioxide gasification and pressurization device of the present invention;

[0026] In the figure: 1. Exhaust electric valve; 2. Exhaust manual valve; 3. Sixth safety valve; 4. Buffer tank; 5. Evaporator check valve; 6. Buffer tank gas phase manual valve; 7. Return pipeline tank manual valve; 8. Buffer tank pressure sensor manual valve; 9. Buffer tank pressure sensor; 10. Level gauge upper valve; 11. Buffer tank level gauge; 12. Return pipeline check valve; 13. 1# main line pressure charging valve; 14. 2# main line pressure charging valve; 15. Level gauge lower valve; 1 6. Shielded pump return check valve; 17. Shielded pump return valve; 18. First pressure sensor; 19. Pump inlet manual valve; 20. Cooling electric valve; 21. Pump cooling drain valve; 22. Electric thermostatic valve; 23. Electric drain valve; 24. First temperature sensor; 25. Third pressure sensor; 26. Main line electric on / off valve; 27. Main line outlet check valve; 28. Third temperature sensor; 29. Discharge outlet manual valve; 30. Third pressure relief valve Valve; 31, third safety valve; 32, discharge interface; 33, second pressure relief valve; 34, fourth safety valve; 35, vaporizer outlet electric valve; 36, vaporizer; 37, pump outlet discharge valve; 38, pump outlet one-way valve; 39, second pressure sensor; 40, pump outlet manual valve; 41, second safety valve; 42, screw pump; 43, flow meter; 44, shielded pump; 45, bellows; 46, filter; 47, first pressure relief valve; 48, first 1. Safety valve; 49. Manual valve at main line outlet; 50. Electric drain valve; 51. Drain switch valve; 52. Buffer tank inlet switch valve; 53. Evaporator inlet switch valve; 54. Evaporator; 55. Fifth pressure relief valve; 56. Seventh safety valve; 57. Filling switch valve; 58. Eighth safety valve; 59. Sixth pressure relief valve; 60. Filling interface; 61. Charging interface; 62. Fourth pressure relief valve; 63. Charging switch valve; 64. Fifth safety valve. DETAILED DESCRIPTION

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0028] A carbon dioxide gasification and pressurization device, such as Figure 1As shown, it includes a buffer tank 4 and a boosting pipeline. The buffer tank 4 is connected to the boosting pipeline. The boosting pipeline is provided with a main pipeline outlet manual valve 49, a first safety valve 48, a first pressure relief valve 47, a filter 46, a bellows 45, a shielded pump 44, a flow meter 43, a first pressure sensor 18, a pump inlet manual valve 19, a screw pump 42, a second safety valve 41, a pump outlet manual valve 40, a second pressure sensor 39, a pump outlet one-way valve 38, a pump body cooling drain valve 21, a pump outlet liquid discharge valve 37, a vaporizer 36, and a vaporizer outlet electric valve. 35, a second pressure relief valve 33, a first temperature sensor 24, a third pressure sensor 25, a main line electric on-off valve 26, a main line outlet one-way valve 27, a third temperature sensor 28, a discharge outlet manual valve 29, a third pressure relief valve 30 and a discharge interface 32. The discharge interface 32 is located at the end of the boosting pipeline away from the buffer tank 4. A fourth safety valve 34 is arranged in parallel with the second pressure relief valve 33, a third safety valve 31 is arranged in parallel with the third pressure relief valve 30, and an electric drain valve 23 is arranged in parallel with the third pressure sensor 25.

[0029] During on-site construction, liquid carbon dioxide enters the boosting pipeline from the buffer tank 4 through the manual valve 49 at the main pipeline outlet, is filtered by the filter 46, and enters the shielded pump 44. The shielded pump 44 is a centrifugal pump, and the liquid supply displacement is slightly larger than the displacement of the screw pump 42 to ensure the smooth operation of the boosting pump 42. The liquid carbon dioxide is discharged from the shielded pump 44, enters the screw pump 42 through the flow meter 43, and the screw pump 42 pressurizes the liquid carbon dioxide and enters the vaporizer 36. The fully vaporized gaseous carbon dioxide is discharged from the discharge interface 32, realizing continuous and stable gas supply.

[0030] Furthermore, the carbon dioxide gasification and pressurization device also includes a charging pipeline, a 1# main pipeline and a 2# main pipeline respectively connected to the buffer tank 4, and the charging pipeline is provided with a charging interface 61, a fourth pressure relief valve 62, a charging switch valve 63, a seventh safety valve 56, a fifth pressure relief valve 55 and a buffer tank liquid inlet switch valve 52 (i.e., the first buffer tank liquid inlet switch valve) in sequence, and a fifth safety valve 64 is provided in parallel with the fourth pressure relief valve 62. The charging interface 61 is located at the end of the charging pipeline away from the buffer tank; one end of the 1# main pipeline is connected to the buffer tank 4, and the other end is connected to the pressurization pipeline, and the connection point is located at the gasifier 36 and the gas The reflux pipeline tank manual valve 7, the 1# main line pressure-charging valve 13, the cooling electric valve 20 and the electric temperature-regulating valve 22 are sequentially arranged on the 1# main line. The reflux pipeline tank manual valve 7 is located at one end of the 1# main line close to the buffer tank 4; the 2# main line is parallel to the 1# main line, one end of the 2# main line is connected between the 1# main line pressure-charging valve 13 and the cooling electric valve 20, and the other end of the 2# main line is connected between the main line outlet manual valve 49 and the first safety valve 48 (that is, connected to the front end of the screw pump 42), and the 2# main line is provided with a 2# main line pressure-charging valve.

[0031] Gaseous carbon dioxide at a certain pressure enters through the charging interface 61, passes through the charging switch valve 63 and the buffer tank liquid inlet switch valve 52, enters the buffer tank 4, and then passes through the 1# main line charging valve 13 and the 2# main line charging valve 14 to respectively charge the screw pump 42 front and back to ensure that the pressure of the entire pipeline system is sufficient, preparing for the buffer tank 4 to be filled with liquid carbon dioxide.

[0032] Furthermore, the carbon dioxide gasification and pressurization device also includes a liquid filling pipeline connected to the buffer tank 4. The liquid filling pipeline is connected in parallel with the pressure charging pipeline. The connection point where the liquid filling pipeline is merged into the pressure charging pipeline is located at the pressure charging switch valve 63 and the seventh safety valve 56. The pipeline before the liquid filling pipeline is merged into the pressure charging pipeline is provided with a liquid filling interface 60, a sixth pressure relief valve 59 and a liquid filling switch valve 57 in sequence. An eighth safety valve 58 is provided in parallel with the sixth pressure relief valve 59. The liquid filling interface is located at the end of the liquid filling pipeline away from the buffer tank. Among them, the liquid filling pipeline and the pressure charging pipeline share the buffer tank liquid inlet switch valve 52 (that is, the second buffer tank liquid inlet switch valve on the liquid filling pipeline). The buffer tank 4 is provided with an exhaust electric valve 1.

[0033] The buffer tank 4 has a liquid filling pipeline. Through the opening of the exhaust electric valve 1, liquid carbon dioxide enters through the liquid filling interface 60, passes through the liquid filling switch valve 57, and the buffer tank liquid inlet switch valve 52, and enters the buffer tank 4, completing the liquid filling process and preparing for the subsequent cold pump.

[0034] Furthermore, the CO2 gasification and pressurization device also includes a self-pressurization pipeline, both ends of which are connected to the buffer tank 4. The self-pressurization pipeline is equipped with, from bottom to top, an evaporator liquid inlet switching valve 53, an evaporator 54, an evaporator check valve 5, and a buffer tank gas phase manual valve 6. The pipeline containing the regulating exhaust electric valve 1 is connected in parallel with the self-pressurization pipeline, with the parallel connection point located between the evaporator check valve 5 and the buffer tank gas phase manual valve 6. An exhaust manual valve 2 and a sixth safety valve are installed between the exhaust electric valve 1 and the buffer tank gas phase manual valve 6.

[0035] The buffer tank 4 is equipped with a self-pressurizing pipeline. The liquid carbon dioxide in the buffer tank 4 enters the evaporator 54 through the evaporator liquid inlet switch valve 53 by its own weight, and the pressurized gaseous carbon dioxide returns to the buffer tank 4, thereby increasing the pressure in the buffer tank 4, preventing the liquid carbon dioxide from gasifying during the pumping process, and ensuring the smooth operation of the device.

[0036] Furthermore, the carbon dioxide gasification and boosting device also includes a return pipeline, one end of which is connected to the buffer tank 4, and the other end is connected to the boosting pipeline and is arranged at the outlet end of the gasifier 36; the return pipeline is provided with an electric temperature regulating valve 22, a cooling electric valve 20 and a return pipeline one-way valve 12 in sequence, and the return pipeline one-way valve 12 is located at one end of the return pipeline close to the buffer tank.

[0037] The outlet pipeline of the vaporizer 36 is divided into two parallel routes, one of which goes to the discharge interface 32. During on-site construction, during normal pressurized gasification, the gaseous carbon dioxide passes through this route. If the reading of the first temperature sensor 24 is too large during the gasification process, the control system will automatically open the electric thermostatic valve 22, and the liquid carbon dioxide will cool the gaseous carbon dioxide after gasification to ensure that the temperature after gasification is within the range of T1-T2; the other route is the reflux pipeline. During the cold pump process, the liquid carbon dioxide passes through the shielded pump 44 and the screw pump 42, and then flows back to the buffer tank 4 through the cooling electric valve 20 and the reflux pipeline one-way valve 12. The internal circulation reflux ensures the complete cold pump while saving carbon dioxide.

[0038] Furthermore, the carbon dioxide gasification and pressurization device also includes a liquid level regulating pipeline, the two ends of the regulating pipeline are connected to the buffer tank 4 at a high position and a low position respectively, and the liquid level regulating pipeline is provided with a liquid level gauge upper valve 10, a buffer tank liquid level gauge 11 and a liquid level gauge lower valve 15 from top to bottom; the buffer tank 4 is also provided with a buffer tank pressure sensor manual valve 8 and a buffer tank pressure sensor 9.

[0039] Based on the above-mentioned carbon dioxide gasification and pressurization device, a carbon dioxide gasification and pressurization method includes:

[0040] (1) Pressurization

[0041] Close the main line electric switch valve 26, open the 1# main line pressure valve 13, 2# main line pressure valve 14, pump inlet manual valve 19, pump outlet manual valve 40, cooling electric valve 20, electric thermostatic valve 22, and finally open the pressure switch valve 63 to charge the buffer tank 4 and the inlet and outlet pipelines of the screw pump 42. Observe the buffer tank pressure sensor 9. When the pressure reaches P o When the pressure is charged, it is completed.

[0042] (2) Cooling

[0043] ① Buffer tank liquid filling: open the liquid filling switch valve 57, adjust the exhaust electric valve 1 within the range of 30%-40%, exhaust and fill the liquid at the same time, observe the liquid level gauge 11, when the liquid level reaches 2 / 3, close the exhaust electric valve 1 and the liquid filling switch valve 57;

[0044] ② Buffer tank self-pressurization: Open the evaporator liquid inlet switch valve 53, and the liquid carbon dioxide in the buffer tank 4 flows into the evaporator 54 by its own weight, which increases the pressure of the buffer tank 4 and reduces the gasification of the liquid carbon dioxide during the cold pump process;

[0045] ③ Cold pump: Cool the electric valve 20, the electric temperature regulating valve 22, and the vaporizer outlet electric valve 35, open the pump body cooling drain valve 21 to 30%, first open the shielding pump 44, then open the screw pump 42, run at low power, observe the outlet of the pump body cooling drain valve 21, and when dry ice appears, open the cooling electric valve 20, close the pump body cooling drain valve 21, establish an internal cycle for cooling, and complete the cold pump operation.

[0046] (3) Gasification

[0047] ① Gasification preparation stage: After the cold pump is completed, open the liquid filling switch valve 57, open the electric drain valve 23 and the gasifier outlet electric valve 35, start the gasifier 36, and run the screw pump 42 at low power. When the first temperature sensor 24 is at T1-T2 and the pressure sensor 26 is at P1-P2, the preparation stage is completed;

[0048] ② Pressurization stage: Open the main line electric on-off valve 26, close the electric drain valve 23, and increase the operating power of the shielded pump 44 and the screw pump 42 according to site requirements to increase the pressure of the carbon dioxide, start pressurization, and simultaneously adjust the operating power of the gasifier 36 to ensure the pressurization process. During the pressurization process, ensure that the reading of the third pressure sensor 25 is within the range of P1′-P2′ and the reading of the third temperature sensor 28 is within the range of T1-T2;

[0049] ③ Pause Phase: During construction, when short standby is required, the following steps are performed: first, open the electric drain valve 23, then close the main line electric on / off valve 26, reduce the power of the shielded pump 44 and screw pump 42, and place the unit in a standby state. For long standby, the following steps are performed: first, open the cooling electric valve 20, stop the vaporizer 36, then close the vaporizer outlet electric valve 35 and the electric thermostatic valve 22, reduce the power of the shielded pump 44 and screw pump 42, and place the unit in an internal circulation state. The order of the gasification preparation and pressurization phases can be adjusted according to actual needs.

[0050] (4) Pressure relief

[0051] Turn off the screw pump 42 in sequence, then turn off the shielded pump 44, the vaporizer 36, and the main line electric switch valve 26, then close the liquid filling switch valve 57, open the pressure switch valve 63, open the electric drain valve 50 to about 30%, and drain the liquid. When there is no dry ice at the outlet of the electric drain valve 50 and no liquid level is displayed on the liquid level gauge 11, it means that the liquid phase is discharged. Close the pressure switch valve 63, open the exhaust electric valve 1 device and discharge the pipeline pressure to zero.

[0052] In summary, the carbon dioxide gasification and pressurization device in the present invention can complete the steps of pressurization, cooling, self-pressurization, pressurization, gasification, temperature regulation and pressure regulation; the present invention pressurizes liquid carbon dioxide and then gasifies it, and the output gaseous carbon dioxide can maintain a certain pressure and temperature; the temperature and pressure of the output gaseous carbon dioxide of the present invention can be adjusted according to construction requirements to achieve continuous and stable output of gaseous carbon dioxide.

[0053] The present invention provides a carbon dioxide gasification and pressurization method, which can complete the steps of pressurization, cooling, self-pressurization, pressurization, gasification, temperature regulation and pressure regulation, pressurizes liquid carbon dioxide, and then gasifies it. The output gaseous carbon dioxide can maintain a certain pressure and temperature. The temperature and pressure can be adjusted according to construction requirements to achieve continuous and stable output of gaseous carbon dioxide.

[0054] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon dioxide gasification and pressurization device, characterized in that: It includes a buffer tank and a boosting pipeline, the buffer tank is connected to the boosting pipeline, and the boosting pipeline is provided with a filter, a shielded pump, a flow meter, a screw pump, a vaporizer and a discharge interface in sequence, and the discharge interface is located at the end of the boosting pipeline away from the buffer tank; The boost pipeline is also provided with a main line outlet manual valve, a first safety valve, a first pressure relief valve, a bellows, a second safety valve, a pump outlet manual valve, a second pressure sensor, a pump outlet check valve, a pump outlet discharge valve, a vaporizer outlet electric valve, a second pressure relief valve, a first temperature sensor, a third pressure sensor, a main line electric switch valve, a pump body cooling drain valve, a main line outlet check valve, a third temperature sensor, a discharge outlet manual valve, a third pressure relief valve, a fourth safety valve, a third safety valve and an electric drain valve; wherein, the main line outlet manual valve, the first safety valve, the first pressure relief valve, the filter, the bellows, A shielded pump, a flow meter, a screw pump, a second safety valve, a pump outlet manual valve, a second pressure sensor, a pump outlet check valve, a pump body cooling drain valve, a pump outlet liquid discharge valve, a vaporizer, a vaporizer outlet electric valve, a second pressure relief valve, a first temperature sensor, a third pressure sensor, a main line electric on-off valve, a main line outlet check valve, a third temperature sensor, a discharge outlet manual valve, a third pressure relief valve and a discharge interface are arranged in sequence, the second pressure relief valve and the fourth safety valve are arranged in parallel, the third pressure relief valve and the third safety valve are arranged in parallel, and the third pressure sensor and the electric drain valve are arranged in parallel; It also includes a charging pipeline, a No. 1 main pipeline, and a No. 2 main pipeline respectively connected to the buffer tank, wherein a charging interface, a charging switch valve, and a first buffer tank liquid inlet switch valve are sequentially provided on the charging pipeline, and the charging interface is located at the end of the charging pipeline away from the buffer tank; One end of the 1# main line and the 2# main line are respectively connected to the buffer tank, and the other end is respectively connected to the front and rear ends of the screw pump. The 1# main line is provided with a 1# main line charging valve, and the 2# main line is provided with a 2# main line charging valve.

2. The carbon dioxide gasification and pressurization device according to claim 1, characterized in that: It also includes a liquid filling pipeline connected to the buffer tank, on which a liquid filling interface, a liquid filling switch valve and a second buffer tank liquid inlet switch valve are sequentially provided. The liquid filling interface is located at the end of the liquid filling pipeline away from the buffer tank, and the buffer tank is provided with an exhaust electric valve.

3. The carbon dioxide gasification and pressurization device according to claim 2, characterized in that: It also includes a self-pressurizing pipeline, which is provided with an evaporator liquid inlet switch valve, an evaporator and an evaporator one-way valve in sequence from bottom to top, and both ends of the self-pressurizing pipeline are connected to the buffer tank.

4. The carbon dioxide gasification and pressurization device according to claim 3, characterized in that: It also includes a return pipeline, one end of which is connected to the buffer tank, and the other end is connected to the boost pipeline and is arranged at the outlet end of the gasifier; a cooling electric valve and a return pipeline one-way valve are sequentially provided on the return pipeline, and the return pipeline one-way valve is located at one end of the return pipeline close to the buffer tank.

5. A carbon dioxide gasification and pressurization method, characterized in that: The carbon dioxide gasification and pressurization device according to any one of claims 1 to 4 comprises the following steps: pressurization, cooling, gasification and pressure relief.

6. The carbon dioxide gasification and pressurization method according to claim 5, characterized in that: The specific charging process is as follows: close the main line electric switch valve, open the 1# main line pressure valve, 2# main line pressure valve, pump inlet manual valve, pump outlet manual valve, cooling electric valve and charging switch valve in sequence, and pressurize the buffer tank and the screw pump inlet and outlet pipelines. When the buffer tank pressure reaches the preset value, the charging is completed.

7. The carbon dioxide gasification and pressurization method according to claim 5 or 6, characterized in that: The cooling includes: liquid inflow to the buffer tank, self-pressurization of the buffer tank and a cold pump.

8. The carbon dioxide gasification and pressurization method according to claim 7, characterized in that: The buffer tank is filled with liquid by opening the filling switch valve, adjusting the exhaust electric valve within the range of 30%-40%, exhausting and filling the liquid at the same time, and when the liquid level reaches the preset level, closing the exhaust electric valve and the filling switch valve in sequence; The buffer tank self-pressurization is specifically as follows: the evaporator liquid inlet switch valve is opened, and the liquid carbon dioxide in the buffer tank flows into the evaporator by its own weight, and is gasified by the evaporator and then sent into the buffer tank, thereby pressurizing the buffer tank; The specific steps of the cold pump are: open the cooling electric valve, electric temperature regulating valve, and vaporizer outlet electric valve in sequence, open the pump body cooling drain valve to the specified value, start the shielded pump first, then start the screw pump, observe the pump body cooling drain valve outlet, and when dry ice appears, close the pump body cooling drain valve, establish an internal cycle for cooling, and complete the cold pumping.

9. The carbon dioxide gasification and pressurization method according to claim 5 or 6, characterized in that: The gasification includes: a gasification preparation stage, a pressurization stage, and a pause stage. The gasification preparation stage specifically includes: opening the liquid filling switch valve, opening the electric drain valve and the gasifier outlet electric valve, starting the gasifier, and running the screw pump. When the first temperature sensor indicates a value between T1 and T2 and the pressure sensor indicates a value between P1 and P2, the gasification preparation stage is completed. The pressurization stage specifically includes: opening the main line electric switch valve, closing the electric drain valve, increasing the operating power of the shielded pump and the screw pump according to site requirements, increasing the pressure of the carbon dioxide, and starting pressurization. During the pressurization process, the reading of the third pressure sensor is ensured to be within the range of P1′-P2′ and the reading of the third temperature sensor is within the range of T1-T2; The pause stage is specifically as follows: when a short standby is required during the construction process, the operating steps are: first open the electric drain valve, then close the main line electric switch valve, reduce the operating power of the shielded pump and the screw pump, and be in a standby state; the long standby operation steps are: first open the cooling electric valve, stop the gasifier, then close the gasifier outlet electric valve and the electric temperature control valve, reduce the operating power of the shielded pump and the screw pump, and the device is in an internal circulation state.

10. The carbon dioxide gasification and pressurization method according to claim 5 or 6, characterized in that: The pressure relief is specifically: Close the screw pump, shielded pump, vaporizer, main line electric switch valve, and liquid charging switch valve in sequence, open the pressure charging switch valve, and open the electric drain valve to drain the liquid. When there is no dry ice at the outlet of the electric drain valve, it means that the liquid phase is discharged. Close the pressure charging switch valve and open the exhaust electric valve to discharge the pipeline pressure to zero.

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