A waste heat recovery system for carbon dioxide capture rich liquid flash regeneration

Abstract

The present invention provides a carbon dioxide capture rich liquid flash regeneration waste heat recovery system, which belongs to the technical field of carbon dioxide capture, and comprises: an absorption tower, a regeneration tower, a lean-rich liquid heat exchanger and a flash tank, wherein the absorption tower and the regeneration tower are connected through the lean-rich liquid heat exchanger, the top of the regeneration tower is provided with a first cooling heat exchanger, and the flash tank is connected between the lean-rich liquid heat exchanger and the first cooling heat exchanger; the carbon dioxide capture rich liquid flash regeneration waste heat recovery system of the present invention utilizes the low temperature of the rich liquid to sequentially recover the heat of the lean liquid returned from the regeneration tower and the regeneration gas at the top of the regeneration tower, and flashes the rich liquid after a heat exchange through the flash tank to realize partial regeneration of the rich liquid and cooling of the rich liquid, and the cooled rich liquid exchanges heat with the regeneration gas at the top of the regeneration tower, thereby achieving a greater degree of recovery of the waste heat of the returned lean liquid and the regeneration gas at the top of the tower.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, and in particular to a carbon dioxide capture rich liquid flash regeneration waste heat recovery system. Background Art

[0002] The energy consumption of the carbon dioxide capture system is mainly the regeneration steam consumption of the regeneration tower. Since the temperature difference between the lean liquid at the bottom of the regeneration tower and the regeneration gas at the top of the tower is not much, the heat they contain is also relatively close. If the heat is recovered from the rich liquid at the bottom of the absorption tower, only the heat of the lean liquid at the bottom of the tower or one of the streams in the first cooling heat exchanger can be recovered. The temperature of the heated rich liquid is not much different from the temperature of the remaining other stream, and the heat recovery of the other stream cannot be achieved.

[0003] For example, the rich liquid can be connected in series with the lean and rich liquid heat exchanger and the first cooling heat exchanger of the regeneration tower respectively. However, since the lean and rich liquid heat exchanger and the first cooling heat exchanger to which the rich liquid is connected in sequence are connected in series, not only the heat exchange end difference of the overall heat exchanger is doubled, but also the temperature difference between the rich liquid and the lean liquid after heat exchange and the temperature of the regenerated gas at the top of the tower is limited. Therefore, all the heat at the top of the regeneration tower cannot be well utilized. This will cause a large amount of heat at the top of the tower to still need to be cooled by cooling circulating water, resulting in almost half of the heat being wasted. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the defect that in the prior art carbon dioxide capture system, when rich liquid is used to recover lean liquid and the waste heat from the top of the regeneration tower is not able to effectively and completely recover the waste heat, thereby providing a carbon dioxide capture rich liquid flash regeneration waste heat recovery system.

[0005] In order to solve the above technical problems, the present invention provides a carbon dioxide capture rich liquid flash regeneration waste heat recovery system, comprising:

[0006] An absorption tower, adapted to be in communication with the flue gas, and used to contain an absorption liquid inside. The absorption liquid in the absorption tower absorbs carbon dioxide in the flue gas and becomes a rich liquid. The absorption tower is connected to a rich liquid supply pipe, and the rich liquid is suitable for being fed into the regeneration tower through the rich liquid supply pipe;

[0007] A regeneration tower, the interior of which is suitable for containing an absorption liquid, the absorption liquid in the regeneration tower becomes a lean liquid after carbon dioxide is precipitated, the regeneration tower is connected with a lean liquid return pipe, and the lean liquid is suitable for flowing back to the absorption tower through the lean liquid return pipe;

[0008] a lean-rich liquid heat exchanger, connected to the rich liquid supply pipe and the lean liquid return pipe, respectively, for exchanging heat between the rich liquid in the rich liquid supply pipe and the lean liquid in the lean liquid return pipe;

[0009] A first cooling heat exchanger is arranged at the top outlet of the regeneration tower, and is used to recover the waste heat of the regeneration gas at the top of the regeneration tower. The first cooling heat exchanger is connected to the rich liquid supply pipe, and the waste heat of the regeneration gas is recovered through the rich liquid in the rich liquid supply pipe;

[0010] A flash tank is connected to the lean-rich liquid heat exchanger and the first cooling heat exchanger respectively through the rich liquid supply pipe. The rich liquid in the rich liquid supply pipe undergoes a heat exchange in the lean-rich liquid heat exchanger or the first cooling heat exchanger, and then partially flashes in the flash tank. Then, the remaining rich liquid enters the lean-rich liquid heat exchanger or the first cooling heat exchanger for a secondary heat exchange.

[0011] Optionally, the flash tank is connected to an air supply pipeline, and the air supply pipeline is connected to a compressor, and the flash gas in the flash tank is suitable for being compressed by the compressor and then transported to the regeneration tower.

[0012] Optionally, the rich liquid in the absorption tower is pumped into the rich liquid supply pipe, passes through the lean and rich liquid heat exchanger, the flash tank and the first cooling heat exchanger in sequence, and finally enters the regeneration tower.

[0013] Optionally, a spray device is provided at the top of the absorption tower, and the spray device performs circulating spraying through a spray pump, and the outlet of the spray pump is suitable for communicating with the top of the regeneration tower.

[0014] Optionally, the spray device includes: a water receiving tray, which is arranged inside the top of the absorption tower, the water receiving tray has a smoke vent connected to the bottom of the absorption tower, and the water receiving tray has a smoke duct extending upward from the smoke vent.

[0015] Optionally, the top end of the flue gas duct is provided with a waterproof cap.

[0016] Optionally, the top of the absorption tower is provided with a tail gas exhaust port, and the front end of the tail gas exhaust port is provided with a demister above the spray device.

[0017] Optionally, a coarse gas exhaust port is provided at the top of the regeneration tower, and the coarse gas exhaust port is communicated with a gas-liquid separator, and separated water of the gas-liquid separator flows back into the regeneration tower.

[0018] Optionally, a second cooling heat exchanger is further provided at the rear end of the first cooling heat exchanger, and the separated water of the gas-liquid separator passes through the second cooling heat exchanger before entering the regeneration tower.

[0019] Optionally, the absorption tower is provided with a self-circulation pipe, one end of which leads to the absorption liquid at the bottom of the absorption tower, and the other end of which leads to the inner cavity at the top of the absorption tower.

[0020] The technical solution of the present invention has the following advantages:

[0021] 1. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided by the present invention utilizes the low temperature of the rich liquid to sequentially recover the heat of the lean liquid returned from the regeneration tower and the tower top regeneration gas of the regeneration tower, and a flash tank is arranged between the lean and rich liquid heat exchanger and the first cooling heat exchanger, and the rich liquid after the primary heat exchange is flashed and cooled by the flash tank, thereby improving the effect of the secondary heat exchange using the rich liquid, thereby achieving a greater degree of recovery of the waste heat of the returned lean liquid and the tower top regeneration gas.

[0022] 2. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided by the present invention, the rich liquid is first heated by heat exchange with the lean liquid, and then enters the flash tank for flash evaporation, so as to realize partial regeneration of the rich liquid, reduce the regeneration load sent to the regeneration tower, and realize the reduction of steam consumption of the regeneration tower. The flash gas of the rich liquid in the flash tank can be used as the regeneration heating gas at the bottom of the regeneration tower after the temperature is increased by the compressor, which can reduce the energy consumption of the reboiler. Specifically, the flash gas evaporated by the rich liquid through the flash tank is compressed by the compressor and transported to the regeneration tower. The flash gas contains a large amount of water vapor. The temperature of the water vapor is further increased by pressurizing the water vapor, so that the flash gas plays the reboiler function of part of the regeneration tower, thereby reducing the energy consumption of the reboiler.

[0023] 3. In the carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided by the present invention, the rich liquid discharged from the absorption tower is first heat exchanged with the lean liquid returned from the regeneration tower, thereby satisfying the cooling of the lean liquid and ensuring the absorption capacity of the absorption liquid in the absorption tower.

[0024] 4. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided by the present invention can send the spray water in the top spray device of the absorption tower to the regeneration tower, reduce the escape of the absorption liquid at the top of the absorption tower, and reduce the loss of the absorption liquid.

[0025] 5. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided by the present invention can further recover the waste heat of the regeneration gas by exchanging heat between the liquid phase at the bottom of the gas-liquid separator and the regeneration gas in the second cooling heat exchanger, thereby reducing the energy consumption of the regeneration tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1It is a front view of an implementation manner of a carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided in an embodiment of the present invention.

[0028] Figure 2 It is a front view of another embodiment of the carbon dioxide capture rich liquid flash regeneration waste heat recovery system provided in the embodiments of the present invention.

[0029] Description of reference numerals:

[0030] 1. Absorption tower; 2. Regeneration tower; 3. Tail gas exhaust port; 4. Self-circulation pipeline; 5. Self-circulation pump; 6. Self-circulation heat exchanger; 7. Water collection tray; 8. Smoke vent; 9. Waterproof cap; 10. Spray pump; 11. Spray heat exchanger; 12. Defogger; 13. Rich liquid supply pipe; 14. Rich liquid pump; 15. Lean and rich liquid heat exchanger; 16. Flash tank; 17. First cooling heat exchanger; 18. Reboiler; 19. Lean liquid return pipe; 20. Lean liquid pump; 21. Crude gas exhaust port; 22. Gas-liquid separator; 23. Second cooling heat exchanger; 24. Air supply pipeline; 25. Compressor. DETAILED DESCRIPTION

[0031] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. 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 creative work are within the scope of protection of the present invention.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] This embodiment provides a carbon dioxide capture rich liquid flash regeneration waste heat recovery system, which can be used for carbon dioxide recovery from electricity or other industrial flue gas to reduce carbon dioxide emissions.

[0036] like Figure 1 As shown, it includes: an absorption tower 1 and a regeneration tower 2. The absorption tower 1 is used to contain absorption liquid. After the flue gas discharged from the power plant is mixed with the absorption liquid in the absorption tower 1, the absorption liquid absorbs the carbon dioxide in the flue gas and becomes a rich liquid. Then the flue gas is discharged from the exhaust gas exhaust port 3 at the top of the absorption tower 1. The content of carbon dioxide in the discharged flue gas is reduced, which is beneficial to environmental protection.

[0037] like Figure 1 As shown, the absorption tower 1 is provided with a self-circulating pipe 4, one end of which leads to the absorption liquid at the bottom of the absorption tower 1, and the other end of which leads to the inner cavity at the top of the absorption tower 1. The self-circulating pipe 4 is provided with a self-circulating pump 5, which is used to pump the absorption liquid from the bottom of the tower to the top of the tower, and then under the action of gravity, the absorption liquid falls from the top of the tower to the bottom of the tower in the absorption tower 1, and is fully in contact with the flue gas during the falling process. In addition, the self-circulating pipe 4 is provided with a self-circulating heat exchanger 6, which is used to reduce the temperature of the absorption liquid in the self-circulating pipe 4, thereby improving the absorption capacity of the absorption liquid.

[0038] like Figure 1As shown, the top of the absorption tower 1 is provided with a spray device, and the spray device circulates and sprays the spray liquid through a spray pump 10, thereby cooling the saturated flue gas and condensing condensed water, which contains absorbent, thereby reducing the absorbent from the top of the absorption tower 1. Specifically, the spray device includes: a water receiving tray 7, which is arranged inside the top of the absorption tower 1, and the water receiving tray 7 has a smoke outlet 8 connected to the bottom of the absorption tower 1, and the water receiving tray 7 has a smoke pipe extending upward from the smoke outlet 8, and the top of the smoke pipe has a waterproof cap 9. The smoke in the absorption tower 1 goes up through the smoke outlet 8, and then passes through the smoke channel from the waterproof cap 9 to the spray area. Then, the spray liquid in the above-mentioned spray device is fully mixed with the flue gas, and the absorption liquid is precipitated from the flue gas while cooling the flue gas, so as to prevent the absorption liquid from being brought into the atmosphere by the flue gas. The water receiving pan 7 is connected to the inlet of the spray pump 10 through a pipeline, and the outlet of the spray pump 10 is connected to a tee, through which the spray liquid can be passed to the top of the regeneration tower 2, so that the spray liquid containing the absorbent can be added to the regeneration tower 2; in addition, the spray liquid can also be passed to the top spray area of ​​the absorption tower 1 through the tee, so that the spray liquid can achieve the purpose of circulating spraying, and the spray heat exchanger 11 is connected to the spray pipe of the spray liquid to reduce the temperature of the spray liquid, improve the cooling effect on the flue gas, and ensure the precipitation effect of the absorbent in the flue gas. That is to say, in the spray area of ​​the absorption tower 1, the saturated flue gas is cooled and condensed to form condensed water, which enters the water receiving pan 7 with the spray liquid, and is sent to the spray heat exchanger 11 through the spray pump 10 for heat exchange and then circulated spraying, and the condensed excess water is sent to the top of the regeneration tower 2 and mixed with the separated water at the bottom of the gas-liquid separator 22 and then enters the top of the regeneration tower 2. In addition, as a preferred embodiment, the front end of the exhaust port 3 at the top of the absorption tower 1 is provided with a demister 12 above the spray device, and the demister 12 is used to further reduce the amount of water contained in the flue gas.

[0039] like Figure 1As shown, the absorption tower 1 is connected with a rich liquid supply pipe 13, and the rich liquid at the bottom of the absorption tower 1 is suitable for being sent to the regeneration tower 2 through the rich liquid supply pipe 13. Specifically, the rich liquid at the bottom of the absorption tower 1 is extracted from the absorption tower 1 by the rich liquid pump 14, and then passes through the lean-rich liquid heat exchanger 15, the flash tank 16 and the first cooling heat exchanger 17 in sequence, and finally enters the regeneration tower 2. In addition, as an alternative embodiment, the rich liquid at the bottom of the absorption tower 1 is extracted from the absorption tower 1 by the rich liquid pump 14, and then passes through the first cooling heat exchanger 17, the flash tank 16 and the lean-rich liquid heat exchanger 15 in sequence, and finally enters the regeneration tower 2. The flash tank 16 is located between the lean-rich liquid heat exchanger 15 and the first cooling heat exchanger 17. The rich liquid is flashed into gas and partially becomes semi-rich liquid after flashing in the flash tank 16. The temperature of the semi-rich liquid is lower than that of the rich liquid before entering the flash tank 16. Therefore, the waste heat recovery of the top regeneration gas of the regeneration tower 2 through the semi-rich liquid can improve the recovery effect.

[0040] The carbon dioxide capture rich liquid flash regeneration waste heat recovery system of this example uses the low temperature of the rich liquid to sequentially recover the heat of the lean liquid returned from the regeneration tower 2 and the tower top regeneration gas of the regeneration tower 2, and a flash tank 16 is arranged between the lean and rich liquid heat exchanger 15 and the first cooling heat exchanger 17. The lean liquid after the first heat exchange is flashed and cooled by the flash tank 16, thereby improving the effect of the secondary heat exchange using the rich liquid, thereby achieving a greater degree of recovery of the waste heat of the returned lean liquid and the tower top regeneration gas.

[0041] like Figure 1 As shown, the interior of the regeneration tower 2 is suitable for accommodating an absorption liquid, and the absorption liquid in the regeneration tower 2 is a rich liquid flowing in from the absorption tower 1, and the rich liquid becomes a lean liquid after being heated to precipitate carbon dioxide. Specifically, a reboiler 18 is connected to the bottom of the regeneration tower 2, and the reboiler 18 is used to heat the rich liquid in the regeneration tower 2, so that the carbon dioxide in the rich liquid is precipitated to become a lean liquid, and the reboiler 18 heats the absorption liquid for heat exchange through the exhaust of the steam turbine.

[0042] like Figure 1 As shown, the regeneration tower 2 is connected with a lean liquid return pipe 19, and the lean liquid at the bottom of the regeneration tower 2 is suitable for flowing back into the absorption tower 1 through the lean liquid return pipe 19. Specifically, the lean liquid at the bottom of the regeneration tower 2 is pumped out from the regeneration tower 2 by the lean liquid pump 20, passes through the lean-rich liquid heat exchanger 15 and the lean liquid cooling heat exchanger in sequence, and finally enters the absorption tower 1 to continue absorbing carbon dioxide in the flue gas.

[0043] like Figure 1As shown, the lean and rich liquid heat exchanger 15 is connected to the rich liquid supply pipe 13 and the lean liquid return pipe 19 respectively, and is used to perform heat exchange between the rich liquid in the rich liquid supply pipe 13 and the lean liquid in the lean liquid return pipe 19, so as to utilize the temperature of the lean liquid returned from the regeneration tower 2 to heat the rich liquid that is about to enter the regeneration tower 2, so as to achieve the purpose of recovering the waste heat of the lean liquid returned from the regeneration tower 2, reduce the temperature of the lean liquid returned from the regeneration tower 2, improve the absorption capacity of the lean liquid for carbon dioxide in the absorption tower 1, and reduce the energy consumption of the regeneration tower 2.

[0044] like Figure 1 As shown, the top outlet of the regeneration tower 2 is a crude gas outlet 21, and the carbon dioxide gas precipitated from the regeneration tower 2 enters the gas-liquid separator 22 through the crude gas outlet 21, and the high-purity carbon dioxide gas is separated by the gas-liquid separator 22, and the carbon dioxide gas is sent to the subsequent compression unit. The liquid phase separated from the gas-liquid separator 22 can flow back into the regeneration tower 2. Specifically, the crude gas outlet 21 of the regeneration tower 2 is connected to the first cooling heat exchanger 17, and the first cooling heat exchanger 17 is used to recover the waste heat of the top regeneration gas of the regeneration tower 2; and the first cooling heat exchanger 17 is connected to the rich liquid supply pipe 13, and the waste heat of the regeneration gas is recovered through the rich liquid in the rich liquid supply pipe 13, thereby realizing the internal circulation of the system.

[0045] like Figure 2 As shown, as an alternative embodiment, a second cooling heat exchanger 23 is further provided at the rear end of the first cooling heat exchanger 17 , and the separated water of the gas-liquid separator 22 passes through the second cooling heat exchanger 23 and then enters the regeneration tower 2 .

[0046] like Figure 1 As shown, the flash tank 16 is connected to a gas supply pipeline 24, and the flash gas produced by flashing the rich liquid through the flash tank 16 is transported to the regeneration tower 2 through the gas supply pipeline 24. The flash gas includes carbon dioxide gas and water vapor, which contains a large amount of heat. After being sent to the regeneration tower 2, it can play the role of the reboiler 18 on the regeneration tower 2.

[0047] In addition, as a preferred embodiment, Figure 1 As shown, the air delivery pipe 24 is connected to a compressor 25, and the flash gas of the flash tank 16 is suitable for being compressed by the compressor 25 and then transported to the regeneration tower 2. The flash gas evaporated by the rich liquid through the flash tank 16 is compressed by the compressor 25 and then transported to the regeneration tower 2. The flash gas contains a large amount of water vapor, and the temperature of the water vapor is further increased by pressurizing the water vapor, so that the flash gas plays a part of the function of the reboiler 18 of the regeneration tower 2, thereby reducing the energy consumption of the reboiler 18.

[0048] Obviously, the above embodiments are merely examples for clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from these are still within the scope of protection of the present invention.

Claims

1. A carbon dioxide capture rich liquid flash regeneration waste heat recovery system, characterized in that: include: An absorption tower (1) is adapted to be in communication with flue gas and is used to contain an absorption liquid inside. The absorption liquid in the absorption tower (1) absorbs carbon dioxide in the flue gas and becomes a rich liquid. A rich liquid supply pipe (13) is connected to the absorption tower (1). The rich liquid is adapted to be fed into the regeneration tower (2) through the rich liquid supply pipe (13); A regeneration tower (2) having an interior adapted to contain an absorption liquid, wherein the absorption liquid in the regeneration tower (2) becomes a lean liquid after carbon dioxide is precipitated, and the regeneration tower (2) is connected to a lean liquid return pipe (19), and the lean liquid is adapted to flow back to the absorption tower (1) through the lean liquid return pipe (19); a lean-rich liquid heat exchanger (15), connected to the rich liquid supply pipe (13) and the lean liquid return pipe (19), respectively, for performing heat exchange between the rich liquid in the rich liquid supply pipe (13) and the lean liquid in the lean liquid return pipe (19); A first cooling heat exchanger (17) is arranged at the top outlet of the regeneration tower (2) and is used to recover waste heat from the regeneration gas at the top of the regeneration tower (2); the first cooling heat exchanger (17) is connected to the rich liquid supply pipe (13) and recovers waste heat from the regeneration gas through the rich liquid in the rich liquid supply pipe (13); A flash tank (16) is connected to the lean-rich liquid heat exchanger (15) and the first cooling heat exchanger (17) respectively through the rich liquid supply pipe (13); the rich liquid in the rich liquid supply pipe (13) is subjected to a primary heat exchange in the lean-rich liquid heat exchanger (15) or the first cooling heat exchanger (17), and then partially flashed in the flash tank (16); then the remaining rich liquid enters the lean-rich liquid heat exchanger (15) or the first cooling heat exchanger (17) for a secondary heat exchange; the flash tank (16) is connected to an air supply pipe (24); the air supply pipe (24) is connected to a compressor (25); the flash gas in the flash tank (16) is suitable for being compressed by the compressor (25) and then transported to the regeneration tower (2); The rich liquid of the absorption tower (1) is pumped by a rich liquid pump (14) in the rich liquid supply pipe (13), passes through a lean and rich liquid heat exchanger (15), a flash tank (16) and a first cooling heat exchanger (17) in sequence, and finally enters the regeneration tower (2). A spray device is provided at the top of the absorption tower (1), and the spray device performs cyclic spraying through a spray pump (10). The outlet of the spray pump (10) is suitable for being connected to the top of the regeneration tower (2).

2. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to claim 1, characterized in that: The spray device comprises: a water receiving tray (7) arranged inside the top of the absorption tower (1); the water receiving tray (7) having a smoke outlet (8) connected to the bottom of the absorption tower (1); and a smoke duct extending upward from the smoke outlet (8) on the water receiving tray (7).

3. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to claim 2, characterized in that: The top end of the smoke duct is provided with a waterproof cap (9).

4. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to claim 1, characterized in that: The top of the absorption tower (1) is provided with a tail gas exhaust port (3), and the front end of the tail gas exhaust port (3) is provided with a demister (12) above the spray device.

5. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to claim 1, characterized in that: The top of the regeneration tower (2) is provided with a coarse gas exhaust port (21), the coarse gas exhaust port (21) is connected to a gas-liquid separator (22), and the separated water of the gas-liquid separator (22) flows back into the regeneration tower (2).

6. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to claim 5, characterized in that: A second cooling heat exchanger (23) is also provided at the rear end of the first cooling heat exchanger (17), and the separated water of the gas-liquid separator (22) passes through the second cooling heat exchanger (23) and then enters the regeneration tower (2).

7. The carbon dioxide capture rich liquid flash regeneration waste heat recovery system according to any one of claims 1 to 6, characterized in that: The absorption tower (1) is provided with a self-circulating pipe (4), one end of which leads to the absorption liquid at the bottom of the absorption tower (1), and the other end of which leads to the inner cavity at the top of the absorption tower (1).

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