A method to prevent CO 2 Tank emptying loss device

Abstract

The utility model belongs to a method for preventing CO 2 Devices for venting losses from storage tanks; including CO 2 Tank unit, CO 2 The inlet of the storage tank unit is connected to the outlet of the subcooler in the carbon dioxide production system in the cold box. 2 The vent pipe provided on the storage tank unit is connected to the vent main pipe; the vent main pipe is connected to the condensation and liquefaction unit, the condensation and liquefaction unit is connected to the gas-liquid separator, and the liquid phase outlet of the gas-liquid separator is connected to the CO 2 The reflux port of the storage tank unit is connected, and the gas phase outlet of the gas-liquid separator is connected to the instrument gas buffer tank; this can avoid CO 2 It can reduce venting losses, reduce carbon emissions, avoid environmental pollution, achieve the recovery and reuse of effective gas resources, and reduce the production cost of liquid carbon dioxide products.

Description

Technical Field

[0001] The utility model belongs to the technical field of carbon dioxide storage, in particular to a device for preventing loss of a CO2 storage tank due to emptying. Background Art

[0002] The storage of liquid carbon dioxide is pressurized storage. During storage, liquid carbon dioxide will gradually gasify as the ambient temperature rises, causing the pressure of the storage tank to increase. In order to meet the pressure stability requirements of tank drainage and subsequent production stages, manual valves or pressure equalizing valves are usually used to vent and release pressure to achieve pressure stability. This method will cause a large amount of carbon dioxide gas emissions, causing environmental pollution, and a large amount of effective gas resources will be wasted, resulting in an increase in the production cost of liquid carbon dioxide products.

[0003] Based on this, how to prevent the loss of CO2 storage tanks from being vented so as to reduce the cost of liquid carbon dioxide products on the basis of energy conservation and emission reduction has become a technical problem that needs to be solved urgently. Utility Model Content

[0004] The utility model aims to provide a device for preventing the loss of CO2 storage tanks when vented, so as to overcome the defects in the prior art.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A device for preventing venting loss of a CO2 storage tank, the device comprising a CO2 storage tank unit, the inlet of the CO2 storage tank unit being connected to the outlet of a supercooler in a carbon dioxide production system in a cold box, the venting pipe arranged on the CO2 storage tank unit being connected to a venting main pipe; the venting main pipe being connected to a condensation and liquefaction unit, the condensation and liquefaction unit being connected to a gas-liquid separator, the liquid phase outlet of the gas-liquid separator being connected to a reflux port of the CO2 storage tank unit, and the gas phase outlet of the gas-liquid separator being connected to an instrument gas buffer tank.

[0007] The beneficial effects of the utility model are as follows: the utility model abandons the direct venting form in the traditional technology, and condenses and liquefies the vented air by setting a condensation and liquefaction unit to realize the recovery of the vented air; it avoids the defects of causing pollution and wasting effective gas resources, and effectively reduces the production cost of liquid carbon dioxide products; further, in order to achieve energy saving and consumption reduction and avoid the discharge of vented air, the utility model uses the gas phase in the gas-liquid separator as instrument gas to realize the characteristic of making full use of the vented air.

[0008] Preferably, the vent main pipe is also connected to a cold recovery unit.

[0009] Preferably, the cold recovery unit includes a raw gas precooler, the tube side inlet of the raw gas precooler is connected to the vent main pipe, the tube side outlet of the raw gas precooler is connected to the shell side inlet of the raw gas precooler through a raw gas compressor, and the shell side outlet of the raw gas precooler is connected to the inlet of the distillation tower in the carbon dioxide production system in the cold box.

[0010] Preferably, the vent pipe is connected to the middle part of the vent main pipe, the condensation and liquefaction unit is arranged on one side of the vent main pipe, and the cold recovery unit is arranged on the other side of the vent main pipe; the gas phase outlet of the gas-liquid separator is connected to the first tee through the sixth stop valve, the first tee is arranged on the vent main pipe close to the side of the cold recovery unit, and the first stop valve and the second stop valve are provided on the vent main pipe on both sides of the first tee; the second tee is provided on the pipe outlet of the raw gas precooler and the raw gas compressor, and the third end of the second tee is connected to the instrument gas buffer tank; the third stop valve is provided between the second tee and the raw gas compressor, and the fourth stop valve is provided between the third end of the second tee and the instrument gas buffer tank.

[0011] Preferably, the pipe side outlet of the raw gas precooler is connected to the three-stage inlet of the raw gas compressor.

[0012] Preferably, the CO2 storage tank unit is a single storage tank or a combination of multiple storage tanks connected in parallel; the storage tank is a spherical storage tank, a vertical storage tank, or a horizontal storage tank.

[0013] Preferably, the storage tank is provided with a pressure sensor, and the venting pipe of the storage tank is provided with a pressure regulating valve.

[0014] Preferably, the condensation and liquefaction unit includes a condenser and liquefier, the tube-side inlet of the condenser and liquefier is connected to the vent main pipe through a fifth stop valve, and the tube-side outlet of the condenser and liquefier is connected to the inlet of a gas-liquid separator; the shell-side outlet of the condenser and liquefier is connected to an ammonia evaporation separator, an ammonia screw compressor and an ammonia evaporation condenser in sequence through a second regulating valve, and the outlet of the ammonia evaporation condenser is connected to the shell-side inlet of the condenser and liquefier through a first regulating valve.

[0015] Preferably, the condenser-liquefier is provided with a liquid level gauge and a pressure transmitter.

[0016] Preferably, the top of the shell side of the condenser-liquefier is connected to the tail gas treatment device through a breathing valve.

[0017] A device for preventing CO2 tank venting losses is made according to the above scheme. By setting up a condensation and liquefaction unit, condensation reflux of the vented air can be achieved. By setting up a cold recovery unit, effective recovery of the cold of the vented air can be achieved. In combination with an instrument gas buffer tank, the vented air itself can be recycled and reused on the basis of energy saving, so as to reduce the CO2 consumption in the system. The utility model is based on the CO2 storage tank unit, and fully utilizes the released vented air through the above-mentioned device, and combines the re-reflux, cold recovery and use in the system to achieve the characteristics of avoiding CO2 venting losses, further achieving the characteristics of reducing carbon emissions, avoiding environmental pollution, realizing the recycling and reuse of effective gas resources, and reducing the production cost of liquid carbon dioxide products. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model.

[0019] In the figure: 1. spherical storage tank; 2. vertical storage tank; 3. horizontal storage tank; 4. vent main; 5. vent pipeline; 6. carbon dioxide production system; 7. subcooler; 8. cold box; 9. pressure regulating valve; 10. distillation tower; 11. pressure sensor; 12. raw gas compressor; 13. first stop valve; 14. second stop valve; 15. ammonia evaporation separator; 16. ammonia screw compressor; 17. ammonia evaporation condenser; 18. first three-way; 19. second three-way; 20. condenser liquefier; 21. third stop valve; 22. fourth stop valve; 23. raw gas precooler; 24. gas-liquid separator; 25. tail gas treatment device; 26. first regulating valve; 27. second regulating valve; 28. liquid level gauge; 29. ​​pressure transmitter; 30. breathing valve; 31. instrument gas buffer tank; 32. fifth stop valve; 33. sixth stop valve. DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0021] Reference Figure 1As shown, a device for preventing the loss of CO2 storage tank venting includes a CO2 storage tank unit, the inlet of the CO2 storage tank unit is connected to the outlet of the supercooler 7 in the carbon dioxide production system 6 in the cold box 8, the venting pipe 5 provided on the CO2 storage tank unit is connected to the venting main pipe 4; the venting main pipe 4 is connected to the condensation and liquefaction unit, the condensation and liquefaction unit is connected to the gas-liquid separator 24, the liquid phase outlet of the gas-liquid separator 24 is connected to the reflux port of the CO2 storage tank unit, and the gas phase outlet of the gas-liquid separator 24 is connected to the instrument gas buffer tank 31. The utility model is based on the CO2 storage tank unit and is connected to the venting pipe by arranging the condensation and liquefaction unit to realize the liquefaction and recovery of the vented air. On this basis, the unliquefied vented air is separated by arranging the gas-liquid separator 24 and recovered through the instrument gas buffer tank 31, so as to realize the utilization of carbon dioxide by the system under the premise of reducing the cold consumption in the condensation and liquefaction unit, and avoid the venting of carbon dioxide at the same time.

[0022] Furthermore, the exhaust main pipe 4 is also connected to a cold recovery unit. In order to fully utilize the exhaust air, the utility model can not only adopt the aforementioned condensation and liquefaction methods, but also adopt a method of recovering cold from the exhaust air.

[0023] Furthermore, the cold recovery unit includes a raw gas precooler 23, the tube side inlet of the raw gas precooler 23 is connected to the vent main pipe 4, the tube side outlet of the raw gas precooler 23 is connected to the shell side inlet of the raw gas precooler 23 through the raw gas compressor 12, and the shell side outlet of the raw gas precooler 23 is connected to the inlet of the distillation tower 10 in the carbon dioxide production system 6 in the cold box 8. The cold recovery unit described in the utility model mainly performs heat exchange on the compressed gas from the raw gas compressor 12 through the raw gas precooler 23, and precools the compressed gas to reduce the cold consumption in the subsequent process section.

[0024] Furthermore, the vent pipe 5 is connected to the middle part of the vent main pipe 4, the condensation and liquefaction unit is arranged on one side of the vent main pipe 4, and the cold recovery unit is arranged on the other side of the vent main pipe 4; the gas phase outlet of the gas-liquid separator 24 is connected to the first tee 18 through the sixth stop valve 33, the first tee 18 is arranged on the vent main pipe 4 close to the side of the cold recovery unit, and the first stop valve 13 and the second stop valve 14 are provided on the vent main pipe 4 on both sides of the first tee 18; the second tee 19 is provided on the pipe outlet of the raw gas precooler 23 and the raw gas compressor 12, and the third end of the second tee 19 is connected to the instrument gas buffer tank 31; the third stop valve 21 is provided between the second tee 19 and the raw gas compressor 12, and the fourth stop valve 22 is provided between the third end of the second tee 19 and the instrument gas buffer tank 31.

[0025] Furthermore, the pipe outlet of the raw gas precooler 23 is connected to the three-stage inlet of the raw gas compressor 12. The utility model utilizes the pressure in the vent air and sends it to the three stages of the raw gas compressor 12 to reduce the compressor work, reduce power consumption and facilitate recovery.

[0026] Furthermore, the CO2 storage tank unit is a single storage tank or a combination of multiple storage tanks connected in parallel; the storage tanks are a spherical storage tank 1, a vertical storage tank 2, and a horizontal storage tank 3.

[0027] Furthermore, the storage tank is provided with a pressure sensor 11, and the venting pipe 5 of the storage tank is provided with a pressure regulating valve 9.

[0028] Furthermore, the condensation and liquefaction unit includes a condenser and liquefier 20, the tube side inlet of the condenser and liquefier 20 is connected to the vent main pipe 4 through a fifth stop valve 32, and the tube side outlet of the condenser and liquefier 20 is connected to the inlet of a gas-liquid separator 24; the shell side outlet of the condenser and liquefier 20 is connected to the ammonia evaporation separator 15, the ammonia screw compressor 16 and the ammonia evaporation condenser 17 in sequence through a second regulating valve 27, and the outlet of the ammonia evaporation condenser 17 is connected to the shell side inlet of the condenser and liquefier 20 through a first regulating valve 26.

[0029] Furthermore, the condenser liquefier 20 is provided with a liquid level meter 28 and a pressure transmitter 29 .

[0030] Furthermore, the top of the shell side of the condenser-liquefier 20 is connected to the tail gas treatment device 25 via a breathing valve 30 .

[0031] The working principle of the utility model is as follows: the pressure sensor 11 is used to detect the pressure in the storage tank. When the pressure exceeds the preset threshold, the pressure regulating valve 9 is opened to allow the vented air to enter the vent main pipe 4 through the vent pipe 5; the preset threshold of the pressure in the spherical storage tank 1 can be 1.85MPa. When the pressure inside the spherical storage tank 1 is greater than 1.85MPa, the corresponding pressure regulating valve 9 is opened; the preset threshold of the pressure in the vertical storage tank 2 can be 2.1MPa. When the pressure inside the vertical storage tank 2 is greater than 2.1MPa, the corresponding pressure regulating valve 9 is opened; the preset threshold of the pressure in the horizontal storage tank 3 can be 2.1MPa. When the pressure inside the horizontal storage tank 3 is greater than 2.1MPa, the corresponding pressure regulating valve 9 is opened. The process route of the vent air entering the vent main pipe 4 can be adjusted by the corresponding stop valve. Preferably, the first process route is: the vent air is condensed and liquefied through the condensation and liquefaction unit, the liquefied liquid phase is condensed and refluxed, and the liquefied gas phase enters the instrument gas buffer tank 31; the second process route is: after the vent air recovers the cold through the cold recovery unit, a part of it enters the instrument gas buffer tank 31, and the other part enters the carbon dioxide production system 6 after passing through the raw gas compressor 12; the utility model preferably adopts the first process route, and the second process route is adopted when the condensation and liquefaction unit fails or is under maintenance; the above-mentioned method can realize the thorough recycling of the vent air and avoid venting; specifically: when the first process route is adopted, the vent air enters the tube side of the condenser and liquefier 20 and exchanges heat with the refrigerant from the shell side of the condenser and liquefier 20 to realize the condensation and liquefaction of the vent air, and the condensed and liquefied material enters the gas-liquid separator 24 for gas-liquid separation, and the liquid phase after gas-liquid separation is refluxed into the CO2 storage tank unit; gas-liquid separation The gas phase after the reaction enters the first three-way valve 18 through the sixth stop valve 33, the first stop valve 13 is closed, and the second stop valve 14 is opened, so that the gas phase passes through the pipe side of the raw gas precooler 23 and enters the instrument gas buffer tank 31; in the above process, the pressure transmitter 29 detects the pressure in the shell side of the condenser liquefier 20, and the liquid level meter 28 detects the liquid level in the shell side of the condenser liquefier 20. When the pressure transmitter 29 detects that the pressure exceeds 0.08MPa, the second regulating valve 27 is opened to pass the gasified refrigerant gas from the shell side of the condenser liquefier 20 to the instrument gas buffer tank 31. It is sent into the ammonia evaporation separator 15, and then re-sent into the shell side of the condenser liquefier 20 through the ammonia screw compressor 16 and the ammonia evaporation condenser 17; when the liquid level gauge 28 detects that the liquid level exceeds 1500mm, the first regulating valve 26 is closed to prevent the liquid ammonia in the ammonia evaporation condenser 17 from entering the shell side of the condenser liquefier 20; when the pressure transmitter 29 detects that the pressure exceeds 1.8MPa, the breathing valve 30 opens the equipment for emergency pressure relief, and releases the high-pressure harmful gases inside the shell side of the condenser liquefier 20 into the exhaust gas treatment device 25.When the condensation and liquefaction unit fails or is undergoing maintenance, the second process route is adopted. The vent air enters the tube side of the raw gas precooler 23 and exchanges heat with the raw gas in the shell side of the raw gas precooler 23 to achieve the purpose of utilizing the vent air cooling capacity. A part of the reheated vent air enters the instrument gas buffer tank 31 and is used as supplementary air for the instrument air of the entire field; the pressure of the other part of the reheated vent air is about 1.8MPa, so that it directly enters the three stages of the raw gas compressor 12 to achieve the characteristics of reducing the work of the compressor and reducing power consumption (reducing the production cost of the compressor); the above-mentioned arrangement can achieve the characteristic of avoiding CO2 venting loss, further achieving the characteristics of reducing carbon emissions, avoiding environmental pollution, realizing the recycling and reuse of effective gas resources, and reducing the production cost of liquid carbon dioxide products.

[0032] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A device for preventing loss of CO2 storage tanks when vented, the device comprising a CO2 storage tank unit, the inlet of the CO2 storage tank unit being connected to the outlet of a supercooler (7) in a carbon dioxide production system (6) in a cold box (8), characterized in that: The venting pipe (5) provided on the CO2 storage tank unit is connected to the venting main pipe (4); The vent main pipe (4) is connected to the condensation and liquefaction unit, the condensation and liquefaction unit is connected to the gas-liquid separator (24), the liquid phase outlet of the gas-liquid separator (24) is connected to the reflux port of the CO2 storage tank unit, and the gas phase outlet of the gas-liquid separator (24) is connected to the instrument gas buffer tank (31).

2. A device for preventing loss of CO2 storage tank from being emptied according to claim 1, characterized in that: The vent main pipe (4) is also connected to a cold recovery unit.

3. A device for preventing loss of CO2 storage tank from being emptied according to claim 2, characterized in that: The cold recovery unit comprises a raw gas precooler (23), the tube side inlet of the raw gas precooler (23) is connected to the vent main pipe (4), the tube side outlet of the raw gas precooler (23) is connected to the shell side inlet of the raw gas precooler (23) through the raw gas compressor (12), and the shell side outlet of the raw gas precooler (23) is connected to the inlet of the distillation tower (10) in the carbon dioxide production system (6) in the cold box (8).

4. A device for preventing loss of CO2 storage tank from being emptied according to claim 3, characterized in that: The vent pipe (5) is connected to the middle of the vent main pipe (4), the condensation and liquefaction unit is arranged on one side of the vent main pipe (4), and the cold recovery unit is arranged on the other side of the vent main pipe (4); The gas phase outlet of the gas-liquid separator (24) is connected to the first tee (18) via a sixth stop valve (33); the first tee (18) is arranged on the vent main pipe (4) close to the cold recovery unit; the first stop valve (13) and the second stop valve (14) are arranged on the vent main pipe (4) on both sides of the first tee (18); A second tee (19) is provided on the pipe outlet of the raw gas precooler (23) and the raw gas compressor (12), and the third end of the second tee (19) is connected to the instrument gas buffer tank (31); a third stop valve (21) is provided between the second tee (19) and the raw gas compressor (12), and a fourth stop valve (22) is provided between the third end of the second tee (19) and the instrument gas buffer tank (31).

5. The device for preventing loss of CO2 storage tank from being emptied according to claim 3 is characterized in that: The pipe-side outlet of the raw gas precooler (23) is connected to the three-stage inlet of the raw gas compressor (12).

6. The device for preventing loss of CO2 storage tank from being emptied according to claim 1, characterized in that: The CO2 storage tank unit is a single storage tank or a combination of multiple storage tanks connected in parallel; the storage tanks are spherical storage tanks (1), vertical storage tanks (2), and horizontal storage tanks (3).

7. A device for preventing loss of CO2 storage tank from being emptied according to claim 6, characterized in that: The storage tank is provided with a pressure sensor (11), and the venting pipe (5) of the storage tank is provided with a pressure regulating valve (9).

8. A device for preventing loss of CO2 storage tank by emptying according to claim 1 or 4, characterized in that: The condensation and liquefaction unit comprises a condensation and liquefaction device (20), the pipe side inlet of the condensation and liquefaction device (20) is connected to the vent main pipe (4) through a fifth stop valve (32), and the pipe side outlet of the condensation and liquefaction device (20) is connected to the inlet of the gas-liquid separator (24); The shell side outlet of the condenser-liquefier (20) is connected to the ammonia evaporation separator (15), the ammonia screw compressor (16) and the ammonia evaporation condenser (17) in sequence through the second regulating valve (27), and the outlet of the ammonia evaporation condenser (17) is connected to the shell side inlet of the condenser-liquefier (20) through the first regulating valve (26).

9. The device for preventing loss of CO2 storage tank from being emptied according to claim 8, characterized in that: The condenser-liquefier (20) is provided with a liquid level meter (28) and a pressure transmitter (29).

10. The device for preventing CO2 storage tank loss by emptying according to claim 9, characterized in that: The top of the shell side of the condenser-liquefier (20) is connected to the tail gas treatment device (25) via a breathing valve (30).

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