Carbon dioxide trapping and regenerating system

Abstract

The embodiment of the invention provides a carbon dioxide capturing and regenerating system which comprises a regenerating tower, a reboiler, a steam supply unit, a rich liquid supply unit and a waste heat utilization unit, a liquid inlet of the reboiler is communicated with a liquid outlet of the regenerating tower, and a liquid outlet of the reboiler is communicated with a first liquid inlet of the regenerating tower; a steam outlet of the steam supply unit is respectively communicated with a second liquid inlet of the regeneration tower, a high-temperature side inlet of the reboiler and a rich liquid reheater of the rich liquid supply unit; a gas inlet of the waste heat utilization unit is communicated with an exhaust port of the regeneration tower, a liquid inlet of the waste heat utilization unit is respectively communicated with a high-temperature side outlet of the reboiler and a high-temperature side outlet of the rich liquid reheater, and a steam outlet of the waste heat utilization unit is communicated with the steam supply unit. Heat of high-temperature carbon dioxide gas and water vapor discharged by the regeneration tower is used for vaporizing condensed water discharged by the reboiler and the rich liquid reheater into water vapor through the waste heat utilization unit, high-temperature water vapor is supplemented for the regeneration tower, external steam supply is reduced, and heat energy consumption is saved.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of carbon dioxide capture, and specifically relate to a carbon dioxide capture and regeneration system. Background Art

[0002] Carbon dioxide capture technology is a carbon dioxide emission reduction technology with great development potential in the thermal power industry. In the chemical absorption carbon dioxide capture process, the lean liquid in the absorber absorbs the carbon dioxide in the flue gas to obtain rich liquid, which enters the regeneration tower for desorption, and the absorbed lean liquid is recovered and circulated to the absorber. The desorbed carbon dioxide regeneration gas is compressed and purified to obtain high-purity carbon dioxide.

[0003] In the related art, the regeneration tower of the carbon dioxide capture and regeneration system uses steam as a heat source and a reboiler as a heat exchange device for indirect heat exchange. The system has a large steam consumption and a high heat consumption, which leads to high operating costs and poor economy of the system. Summary of the invention

[0004] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a carbon dioxide capture and regeneration system.

[0005] The present disclosure provides a carbon dioxide capture and regeneration system, comprising:

[0006] A regeneration tower, the regeneration tower is used to regenerate carbon dioxide in the rich liquid;

[0007] a reboiler, wherein the liquid inlet of the reboiler is connected to the liquid outlet of the regeneration tower, the liquid outlet of the reboiler is connected to the first liquid inlet of the regeneration tower, and the reboiler is used to vaporize the solution at the bottom of the regeneration tower;

[0008] A steam supply unit, the steam supply unit comprising a first steam pipeline, a second steam pipeline and a third steam pipeline, the first steam pipeline being connected to a high temperature side inlet of the reboiler, and the second steam pipeline being connected to a second liquid inlet of the regeneration tower;

[0009] A rich liquid supply unit, the rich liquid supply unit comprising a first rich liquid pipeline, the first rich liquid pipeline being in communication with the third liquid inlet of the regeneration tower, a rich liquid reheater being provided on the first rich liquid pipeline, and a high temperature side inlet of the rich liquid reheater being in communication with the third steam pipeline;

[0010] A waste heat utilization unit, wherein the gas inlet of the waste heat utilization unit is connected to the exhaust port of the regeneration tower, the liquid inlet of the waste heat utilization unit is connected to the high-temperature side outlet of the reboiler and the high-temperature side outlet of the rich liquid reheater respectively, the steam outlet of the waste heat utilization unit is connected to the steam supply unit, and the waste heat utilization unit is used to utilize the heat of the regeneration gas discharged from the regeneration tower to vaporize the liquid discharged from the reboiler and the rich liquid reheater.

[0011] In some embodiments of the present disclosure, the waste heat utilization unit includes:

[0012] an evaporator, wherein a high temperature side inlet of the evaporator is connected to an exhaust port of the regenerator;

[0013] A condenser, wherein a low temperature side inlet of the condenser is connected to a high temperature side outlet of the reboiler and a high temperature side outlet of the rich liquid reheater, respectively, and the high temperature side outlet of the condenser is connected to the steam supply unit;

[0014] A first circulating medium pipeline, the first circulating medium pipeline is connected to the low-temperature side outlet of the evaporator and the high-temperature side inlet of the condenser, and a compressor is provided on the first circulating medium pipeline;

[0015] The second circulating medium pipeline is connected with the low-temperature side inlet of the evaporator and the high-temperature side outlet of the condenser, and a throttle is arranged on the second circulating medium pipeline.

[0016] In some embodiments of the present disclosure, the gas-liquid mixing outlet of the waste heat utilization unit is connected to a gas-liquid separator.

[0017] In some embodiments of the present disclosure, the carbon dioxide capture and regeneration system further comprises: a hydrophobic unit, the hydrophobic unit comprising:

[0018] A steam trap, wherein a first water inlet of the steam trap is communicated with a high temperature side outlet of the reboiler, a second water inlet of the steam trap is communicated with a high temperature side outlet of the rich liquid reheater, and a drain outlet of the steam trap is communicated with a liquid inlet of the waste heat utilization unit;

[0019] A cooler is connected to the steam trap through a circulating cooling pipeline, and the cooler is used to cool the water vapor in the steam trap.

[0020] In some embodiments of the present disclosure, the steam supply unit also includes a steam storage tank, a steam outlet of the steam storage tank is respectively connected to the first steam pipeline, the second steam pipeline and the third steam pipeline, and a steam inlet of the steam storage tank is connected to the steam outlet of the waste heat utilization unit.

[0021] In some embodiments of the present disclosure, the steam supply unit also includes a temperature and pressure reduction device, the inlet of the pressure reduction and temperature reduction system is connected to the high-temperature and high-pressure steam pipeline, and the steam outlet of the pressure reduction and temperature reduction system is connected to the steam inlet of the steam storage tank.

[0022] In some embodiments of the present disclosure, the rich liquid supply unit also includes a second rich liquid pipeline, which is connected to the fourth liquid inlet of the regeneration tower, the fourth liquid inlet is located at the top of the regeneration tower, and the third liquid inlet is located below the fourth liquid inlet.

[0023] In some embodiments of the present disclosure, the rich liquid supply unit also includes a lean and rich liquid heat exchanger, which is arranged in the first rich liquid pipeline. Along the flow direction of the rich liquid, the rich liquid reheater is located in front of the lean and rich liquid heat exchanger.

[0024] According to the carbon dioxide capture and regeneration system of the embodiment of the present disclosure, the high-temperature carbon dioxide and water vapor discharged from the regeneration tower enter the waste heat utilization unit through the gas inlet of the waste heat utilization unit, release heat to become low-temperature carbon dioxide and condensed water, and then the low-temperature carbon dioxide and condensed water are discharged from the gas-liquid outlet of the waste heat utilization unit; the condensed water discharged from the high-temperature side outlet of the reboiler and the high-temperature side outlet of the rich liquid reheater enters the waste heat utilization unit through the liquid inlet of the waste heat utilization unit, absorbs heat and vaporizes into high-temperature water vapor, the water vapor is discharged from the steam outlet of the waste heat utilization unit, and then enters the first steam pipeline, the second steam pipeline and the third steam pipeline of the steam supply unit, The water vapor entering the first steam pipeline enters the reboiler through the high-temperature side inlet of the reboiler, flows through the reboiler to release heat to vaporize the solution discharged from the regeneration tower, and becomes condensed water after releasing heat and is discharged from the high-temperature side outlet of the reboiler. The water vapor entering the second steam pipeline enters the regeneration tower through the second liquid inlet to provide heat and moisture for the regeneration tower. The water vapor entering the third steam pipeline enters the rich liquid reheater through the high-temperature side inlet of the rich liquid reheater, flows through the rich liquid reheater to release heat to heat the rich liquid flowing through the rich liquid reheater, and becomes condensed water after releasing heat and is discharged from the high-temperature side outlet of the rich liquid reheater. The heat of the relatively high-temperature carbon dioxide gas and water vapor discharged from the regeneration tower is used through the waste heat utilization unit to vaporize the condensed water discharged from the reboiler and the rich liquid reheater into high-temperature water vapor, thereby providing heat and moisture to the regeneration tower, providing thermal energy for the reboiler to vaporize the solution in the regeneration tower, and providing thermal energy for the rich liquid reheater to vaporize the rich liquid, thereby improving the waste heat utilization rate of the regeneration tower, saving heat energy consumption, reducing system operating costs, and improving the economy of the system.

[0025] The carbon dioxide capture and regeneration system disclosed in the present invention has the following beneficial effects:

[0026] 1. The heat of the high-temperature gas in the regeneration tower is used to heat the condensed water to provide a steam heat source for the regeneration tower, which can reduce the supply of external steam, save heat consumption, and reduce operating costs;

[0027] 2. By introducing steam into the regeneration tower to directly heat the regeneration tower solution, the heat exchange efficiency is improved, and water is added to the system, which is beneficial to the water balance of the system.

[0028] 3. Usually, the rich liquid temperature at the outlet of the lean-rich liquid exchanger is lower than the temperature of the bottom solution of the regeneration tower. Compared with heating the bottom solution of the regeneration tower, heating the rich liquid at the outlet of the lean-rich liquid exchanger has higher heat exchange efficiency, which can further reduce the heat load of the reheater and the steam consumption of the regeneration system, thereby reducing operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic structural diagram of a carbon dioxide capture and regeneration system according to an embodiment of the present disclosure.

[0030] The reference numerals in the accompanying drawings represent the following:

[0031] 100. Carbon dioxide capture and regeneration system;

[0032] 10. Regeneration tower;

[0033] 20. Reboiler;

[0034] 30. Steam supply unit; 31. First steam pipeline; 32. Second steam pipeline; 33. Third steam pipeline; 34. Steam storage tank; 35. Temperature and pressure reduction device; 36. High-temperature and high-pressure steam pipeline;

[0035] 40. Rich liquid supply unit; 41. First rich liquid pipeline; 42. Second rich liquid pipeline; 43. Rich liquid reheater; 44. Lean and rich liquid heat exchanger;

[0036] 50. Waste heat utilization unit; 51. Evaporator; 52. Condenser; 53. Compressor; 54. Throttle; 55. First medium circulation pipeline; 56. Second circulation medium pipeline; 57. Gas-liquid separator;

[0037] 60. Drain unit; 61. Drain; 62. Cooler. DETAILED DESCRIPTION

[0038] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0039] It should be understood that the terms used herein are only for the purpose of describing specific example embodiments and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "include", "comprise", "contain", and "have" are inclusive, and therefore specify the existence of stated features, steps, operations, elements and / or parts, but do not exclude the existence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not interpreted as necessarily requiring them to be performed in the specific order described or illustrated, unless the execution order is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0040] Although the terms first, second, third, etc. can be used in the text to describe multiple elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms can only be used to distinguish an element, component, region, layer or section from another region, layer or section. Unless the context clearly indicates, terms such as "first", "second" and other numerical terms do not imply order or sequence when used in the text. Therefore, the first element, component, region, layer or section discussed below can be referred to as the second element, component, region, layer or section without departing from the teaching of the example embodiments.

[0041] For ease of description, spatial relative terms may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figure, such as "inside", "outside", "inner side", "outer side", "below", "below", "above", "above", etc. Such spatial relative terms are intended to include different orientations of the device in use or operation in addition to the orientation depicted in the figure. For example, if the device in the figure is turned over, then the elements described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features". Therefore, the example term "below..." can include both upper and lower orientations. The device can be oriented otherwise (rotated 90 degrees or in other directions) and the spatial relative descriptors used in the text are interpreted accordingly.

[0042] like Figure 1As shown, an embodiment of the present disclosure provides a carbon dioxide capture and regeneration system 100, comprising: a regeneration tower 10, a reboiler 20, a steam supply unit 30, a rich liquid supply unit 40 and a waste heat utilization unit 50. Specifically, the regeneration tower 10 is used to desorb carbon dioxide in the rich liquid to regenerate the absorption solution. The liquid inlet of the reboiler 20 is connected to the liquid outlet of the regeneration tower 10, and the liquid outlet of the reboiler 20 is connected to the first liquid inlet of the regeneration tower 10. The reboiler 20 is used to vaporize the solution at the bottom of the regeneration tower 10. The steam supply unit 30 comprises a first steam pipeline 31, a second steam pipeline 32 and a third steam pipeline 33. The first steam pipeline 31 is connected to the high temperature side inlet of the reboiler 20, and the second steam pipeline 32 is connected to the regeneration tower 10. The second liquid inlet of the regeneration tower 10 is connected, the rich liquid supply unit 40 includes a first rich liquid pipeline 41, the first rich liquid pipeline 41 is connected to the third liquid inlet of the regeneration tower 10, a rich liquid reheater 43 is provided on the first rich liquid pipeline 41, the high temperature side inlet of the rich liquid reheater 43 is connected to the third steam pipeline 33, the gas inlet of the waste heat utilization unit 50 is connected to the exhaust port of the regeneration tower 10, the liquid inlet of the waste heat utilization unit 50 is connected to the high temperature side outlet of the reboiler 20 and the high temperature side outlet of the rich liquid reheater 43 respectively, the steam outlet of the waste heat utilization unit 50 is connected to the steam supply unit 30, and the waste heat utilization unit 50 is used to utilize the heat of the regeneration gas discharged from the regeneration tower 10 to vaporize the liquid discharged from the reboiler 20 and the rich liquid reheater 43.

[0043] According to the carbon dioxide capture and regeneration system 100 of the embodiment of the present disclosure, the high-temperature carbon dioxide and water vapor discharged from the regeneration tower 10 enter the waste heat utilization unit 50 through the gas inlet of the waste heat utilization unit 50, release heat to become low-temperature carbon dioxide and condensed water, and then the low-temperature carbon dioxide and condensed water are discharged from the gas-liquid outlet of the waste heat utilization unit 50; the condensed water discharged from the high-temperature side outlet of the reboiler 20 and the high-temperature side outlet of the rich liquid reheater 43 enters the waste heat utilization unit 50 through the liquid inlet of the waste heat utilization unit 50, absorbs heat and vaporizes into water vapor, is discharged from the steam outlet of the waste heat utilization unit 50 and enters the steam supply unit 30, and the water vapor entering the first steam pipeline 31 passes through the hot end high-temperature side inlet of the reboiler 20 The water vapor enters the reboiler 20, flows through the reboiler 20 to release heat so as to vaporize the solution discharged from the regeneration tower 10. After releasing the heat, the water vapor becomes condensed water and is discharged from the high-temperature side outlet of the reboiler 20. The water vapor entering the second steam pipeline 32 enters the regeneration tower 10 through the second liquid inlet to provide heat and moisture for the regeneration tower 10. The water vapor entering the third steam pipeline 33 enters the rich liquid reheater 43 through the high-temperature side inlet of the rich liquid reheater 43, flows through the rich liquid reheater 43 to release heat so as to heat the rich liquid flowing through the rich liquid reheater 43. After releasing the heat, the water vapor becomes condensed water and is discharged from the high-temperature side outlet of the rich liquid reheater 43. After the rich liquid is vaporized, it enters the regeneration tower 10 through the third liquid inlet. The heat of the relatively high-temperature carbon dioxide gas and water vapor discharged from the regeneration tower 10 is used through the waste heat utilization unit 50 to vaporize the condensed water discharged from the reboiler 20 and the rich liquid reheater 43 into high-temperature water vapor, so as to provide heat and moisture to the regeneration tower 10, provide thermal energy to the reboiler 20 to vaporize the solution in the regeneration tower 10, and provide thermal energy to the rich liquid reheater 43 to vaporize the rich liquid, thereby improving the waste heat utilization rate of the regeneration tower 10, reducing the supply of external steam, saving heat energy consumption, reducing the system operating cost, and improving the economy of the system.

[0044] In some embodiments of the present disclosure, the waste heat utilization unit 50 includes: an evaporator 51, a condenser 52, a first circulating medium pipeline 55 and a second circulating medium pipeline 56, the high temperature side inlet of the evaporator 51 is connected to the exhaust port of the regenerator, the low temperature side inlet of the condenser 52 is directly or indirectly connected to the high temperature side outlet of the reboiler 20, the low temperature side inlet of the condenser 52 is directly or indirectly connected to the high temperature side outlet of the rich liquid reheater 43, the low temperature side outlet of the condenser 52 is connected to the steam supply unit 30, the first circulating medium pipeline 55 connects the low temperature side outlet of the evaporator 51 and the high temperature side inlet of the condenser 52, and the second circulating medium pipeline 56 connects the low temperature side inlet of the evaporator 51 and the high temperature side outlet of the condenser 52. The high-temperature carbon dioxide gas and water vapor discharged from the regeneration tower enter the evaporator 51 through the high-temperature side inlet of the evaporator 51, and the high-temperature carbon dioxide gas and water vapor flow through the evaporator 51 to release heat, and become low-temperature carbon dioxide gas and water vapor, and are discharged from the high-temperature side outlet of the evaporator 51; the circulating medium flows into the low-temperature side inlet of the evaporator 51 through the second circulating medium pipeline 56, and the circulating medium flows through the evaporator 51 to absorb the heat released by the high-temperature carbon dioxide and water vapor. The circulating medium after absorbing the heat is discharged from the low-temperature side outlet of the evaporator 51 and enters the first circulating medium pipeline 55. The circulating medium enters the condenser 52 through the high-temperature side inlet of the condenser 52, and the circulating medium The mass flow releases heat through the condenser 52, and the circulating medium after releasing the heat is discharged from the high-temperature side outlet of the condenser 52 and enters the second circulating medium pipeline 56, thereby realizing the circulation of the circulating medium; the condensed water discharged from the high-temperature side outlet of the reboiler 20 and the condensed water discharged from the high-temperature side outlet of the rich liquid reheater 43 enter the condenser 52 through the low-temperature side inlet of the condenser 52 respectively, the condensed water flows through the condenser 52 to absorb the heat released by the circulating medium, vaporizes into water vapor, and is discharged from the low-temperature side outlet of the condenser 52 to the steam supply unit 30, that is, the water vapor directly or indirectly enters the first steam pipeline 31, the second steam pipeline 32 and the third steam pipeline 33.

[0045] It should be noted that the gas inlet of the waste heat utilization unit 50 in this embodiment is the high temperature side inlet of the evaporator 51, the gas-liquid outlet of the waste heat utilization unit 50 is the high temperature side outlet of the evaporator 51, the liquid inlet of the waste heat utilization unit 50 is the low temperature side inlet of the condenser 52, and the steam outlet of the waste heat utilization unit 50 is the low temperature side outlet of the condenser 52.

[0046] In addition, the high-temperature side in this embodiment refers to the side where the fluid releases heat, for example, high-temperature gas enters the evaporator 51 from the high-temperature side inlet of the evaporator 51, and is discharged through the high-temperature side outlet of the evaporator 51 after releasing heat in the evaporator 51; the low-temperature side refers to the side where the fluid absorbs heat, for example, the cooled liquid enters the condenser 52 from the low-temperature side inlet of the condenser 52, and is discharged through the low-temperature side outlet of the condenser 52 after absorbing heat in the condenser 52.

[0047] Specifically, the circulating medium in this embodiment is fluorine-free refrigerant R410A.

[0048] In some embodiments of the present disclosure, a compressor 53 is provided on the first circulating medium pipeline 55, and the circulating medium is converted into a high-temperature and high-pressure fluid through the work of the compressor 53.

[0049] In some embodiments of the present disclosure, a throttle 54 is provided on the second circulating medium pipeline 56 , and the circulating medium is converted into a low-temperature and low-pressure fluid through the throttle 54 .

[0050] In some embodiments of the present disclosure, the high temperature side outlet of the evaporator 51 of the waste heat utilization unit 50 is connected to the gas-liquid separator 57. Specifically, the high temperature side outlet of the evaporator 51 is connected to the gas-liquid separator 57, and the low temperature carbon dioxide and water vapor discharged from the evaporator 51 are separated into gas and liquid through the gas-liquid separator 57, so as to collect the carbon dioxide and condensed water separately.

[0051] In some embodiments of the present disclosure, the carbon dioxide capture and regeneration system 100 further includes: a drain unit 60, which includes: a drain 61, a first water inlet of the drain 61 is connected to the high temperature side outlet of the reboiler 20, a second water inlet of the drain 61 is connected to the high temperature side outlet of the rich liquid reheater 43, and a drain outlet of the drain 61 is connected to the low temperature side inlet of the condenser 52 of the waste heat utilization unit 50. That is, the high temperature side outlet of the reboiler 20 and the high temperature side outlet of the rich liquid reheater 43 are connected to the low temperature side inlet of the condenser 52 through the drain 61 respectively.

[0052] The drain unit 60 also includes a cooler 62, which is connected to the drain tank 61 through a circulating cooling pipeline. Specifically, the circulating cooling pipeline includes a first circulating cooling pipeline and a second circulating cooling pipeline. The first circulating cooling pipeline connects the steam outlet at the top of the drain tank 61 and the high-temperature side inlet of the cooler 62, and the second circulating cooling pipeline connects the third water inlet at the bottom of the drain tank 61 and the high-temperature side outlet of the cooler 62. The condensed water discharged from the reboiler 20 and the condensed water discharged from the rich liquid reheater 43 both contain a small amount of water vapor. The condensed water containing water vapor enters the steam trap 61. The condensed water is at the bottom of the steam trap 61. The water vapor enters the first circulating cooling pipeline through the steam outlet at the top of the steam trap 61, and then enters the cooler 62 from the high-temperature side inlet. The water vapor flows through the cooler 62 to release heat, liquefies into condensed water, and is discharged from the high-temperature side outlet of the cooler 62 to the second circulating cooling pipeline, and finally enters the steam trap 61 through the third water inlet; the cooling water enters the cooler 62 from the low-temperature side inlet of the cooler 62, the cold water absorbs the heat released by the water vapor, and is discharged from the low-temperature side outlet of the cooler 62.

[0053] In some embodiments of the present disclosure, the steam supply unit 30 further includes a steam storage tank 34, the steam outlet of the steam storage tank 34 is respectively connected to the first steam pipeline 31, the second steam pipeline 32 and the third steam pipeline 33, and the steam inlet of the steam storage tank 34 is connected to the low-temperature side outlet of the condenser 52 of the waste heat utilization unit 50. Specifically, the low-temperature side outlet of the condenser 52 is connected to the steam inlet of the steam storage tank 34 to transport the water vapor to the steam storage tank 34 for temporary storage, and then the water vapor provides heat energy for the reboiler 20 through the first steam pipeline 31, provides water vapor for the regeneration tower 10 through the second steam pipeline 32, and provides heat energy for the rich liquid reheater 43 through the third steam pipeline 33.

[0054] In some embodiments of the present disclosure, the steam supply unit 30 further includes a temperature reduction and pressure reduction device 35, the inlet of the pressure reduction and temperature reduction system is connected to the high-temperature and high-pressure steam pipeline 36, and the steam outlet of the pressure reduction and temperature reduction system is connected to the steam inlet of the steam storage tank 34. The high-temperature and high-pressure water vapor is transported to the temperature reduction and pressure reduction device 35 by the high-temperature and high-pressure steam pipeline 36 to reduce the temperature and pressure of the water vapor. The water vapor after pressure reduction and temperature reduction is discharged from the steam outlet of the temperature reduction and pressure reduction device 35, and enters the steam storage tank 34 through the steam inlet of the steam storage tank 34 for temporary storage. The high-temperature and high-pressure steam pipeline 36 introduces external water vapor into the steam supply unit 30 to ensure that the regeneration tower 10 has sufficient water vapor heat source for use.

[0055] In some embodiments of the present disclosure, the rich liquid supply unit 40 further includes a second rich liquid pipeline 42, the second rich liquid pipeline 42 is connected to the fourth liquid inlet of the regeneration tower 10, the fourth liquid inlet is located at the top of the regeneration tower 10, and the third liquid inlet is located below the fourth liquid inlet. The unheated rich liquid flows through the second rich liquid pipeline 42 and enters the top of the regeneration tower 10 through the fourth liquid inlet. The rich liquid flows downward from the top of the regeneration tower 10, and the carbon dioxide gas and water vapor in the space below the fourth liquid inlet are cooled. Further, the second liquid inlet is located below the third liquid inlet, and the first liquid inlet is located below the second liquid inlet.

[0056] In some embodiments of the present disclosure, the rich liquid supply unit 40 further includes a lean-rich liquid heat exchanger 44, which is disposed in the first rich liquid pipeline 41. Along the flow direction of the rich liquid, the rich liquid reheater 43 is located in front of the lean-rich liquid heat exchanger 44. In the process of the rich liquid flowing from the first rich liquid pipeline 41 to the regeneration tower 10, it first flows through the lean-rich liquid heat exchanger 44, is heated by the lean-rich liquid heat exchanger 44 for the first time, then flows through the rich liquid reheater 43, is heated by the rich liquid reheater 43 for the second time, and finally flows into the regeneration tower 10 through the third liquid inlet. The rich liquid is heated twice to ensure that the rich liquid is vaporized.

[0057] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present disclosure, but the present disclosure is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and substance of the present disclosure, and these modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A carbon dioxide capture and regeneration system, characterized in that: The carbon dioxide capture and regeneration system comprises: A regeneration tower, the regeneration tower is used to regenerate carbon dioxide in the rich liquid; a reboiler, wherein the liquid inlet of the reboiler is connected to the liquid outlet of the regeneration tower, the liquid outlet of the reboiler is connected to the first liquid inlet of the regeneration tower, and the reboiler is used to vaporize the solution at the bottom of the regeneration tower; A steam supply unit, the steam supply unit comprising a first steam pipeline, a second steam pipeline and a third steam pipeline, the first steam pipeline being connected to a high temperature side inlet of the reboiler, and the second steam pipeline being connected to a second liquid inlet of the regeneration tower; A rich liquid supply unit, the rich liquid supply unit comprising a first rich liquid pipeline, the first rich liquid pipeline being in communication with the third liquid inlet of the regeneration tower, a rich liquid reheater being provided on the first rich liquid pipeline, and a high temperature side inlet of the rich liquid reheater being in communication with the third steam pipeline; A waste heat utilization unit, wherein the gas inlet of the waste heat utilization unit is connected to the exhaust port of the regeneration tower, the liquid inlet of the waste heat utilization unit is connected to the high-temperature side outlet of the reboiler and the high-temperature side outlet of the rich liquid reheater respectively, the steam outlet of the waste heat utilization unit is connected to the steam supply unit, and the waste heat utilization unit is used to utilize the heat of the regeneration gas discharged from the regeneration tower to vaporize the liquid discharged from the reboiler and the rich liquid reheater.

2. The carbon dioxide capture and regeneration system according to claim 1, characterized in that: The waste heat utilization unit comprises: an evaporator, wherein a high temperature side inlet of the evaporator is connected to an exhaust port of the regenerator; A condenser, wherein a low-temperature side inlet of the condenser is connected to a high-temperature side outlet of the reboiler and a high-temperature side outlet of the rich liquid reheater, respectively, and the low-temperature side outlet of the condenser is connected to the steam supply unit; A first circulating medium pipeline, the first circulating medium pipeline is connected to the low-temperature side outlet of the evaporator and the high-temperature side inlet of the condenser, and a compressor is provided on the first circulating medium pipeline; The second circulating medium pipeline is connected with the low-temperature side inlet of the evaporator and the high-temperature side outlet of the condenser, and a throttle is arranged on the second circulating medium pipeline.

3. The carbon dioxide capture and regeneration system according to claim 1, characterized in that: The gas-liquid mixing outlet of the waste heat utilization unit is communicated with the gas-liquid separator.

4. The carbon dioxide capture and regeneration system according to claim 1, characterized in that: The carbon dioxide capture and regeneration system further comprises: a hydrophobic unit, wherein the hydrophobic unit comprises: A steam trap, wherein a first water inlet of the steam trap is communicated with a high temperature side outlet of the reboiler, a second water inlet of the steam trap is communicated with a high temperature side outlet of the rich liquid reheater, and a drain outlet of the steam trap is communicated with a liquid inlet of the waste heat utilization unit; A cooler is connected to the steam trap through a circulating cooling pipeline, and the cooler is used to cool the water vapor in the steam trap.

5. The carbon dioxide capture and regeneration system according to claim 1, characterized in that: The steam supply unit further includes a steam storage tank, a steam outlet of the steam storage tank is respectively connected to the first steam pipeline, the second steam pipeline and the third steam pipeline, and a steam inlet of the steam storage tank is connected to the steam outlet of the waste heat utilization unit.

6. The carbon dioxide capture and regeneration system according to claim 5, characterized in that: The steam supply unit also includes a temperature and pressure reduction device, the inlet of the pressure reduction and temperature reduction system is connected to the high-temperature and high-pressure steam pipeline, and the steam outlet of the pressure reduction and temperature reduction system is connected to the steam inlet of the steam storage tank.

7. The carbon dioxide capture and regeneration system according to claim 1, characterized in that: The rich liquid supply unit further includes a second rich liquid pipeline, which is connected to a fourth liquid inlet of the regeneration tower. The fourth liquid inlet is located at the top of the regeneration tower, and the third liquid inlet is located below the fourth liquid inlet.

8. The carbon dioxide capture and regeneration system according to claim 7, characterized in that: The rich liquid supply unit further includes a lean and rich liquid heat exchanger, which is disposed in the first rich liquid pipeline. Along the flow direction of the rich liquid, the rich liquid reheater is located in front of the lean and rich liquid heat exchanger.

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