Regenerated gas heat recovery process system of wet decarburization technology

Abstract

The invention discloses a regeneration gas heat recovery process system for a wet decarburization technology. The regeneration gas heat recovery process system sequentially comprises an absorption unit, a lean and rich liquid heat exchange unit and a regeneration unit which are connected, the regeneration unit comprises a regeneration tower, and a regeneration section and a regeneration gas washing system are sequentially arranged in the regeneration tower from bottom to top; a section of one-way metal pipeline is introduced into the regenerated gas washing system to convey condensate to the front end of a rich liquid pump in the lean and rich liquid heat exchange unit; according to the invention, the regeneration gas washing section is additionally arranged at the upper part of the regeneration tower, the water vapor content in the regeneration gas is reduced through circulating spraying of the washing liquid, and the heat brought by the regeneration gas is reduced, so that the load of the tower top condenser and the regeneration energy consumption in the desorption process are reduced; secondly, the gas-liquid mass transfer effect can be enhanced through forced circulation spraying, and the operation loss of the absorbent is reduced; in addition, all condensed liquid in the process is collected to the rich liquid, so that the alkalinity of the rich liquid can be reduced, and sufficient desorption of carbon dioxide is facilitated.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, and particularly relates to a heat recovery process system for the regenerated gas of a wet decarbonization technology. Background Art

[0002] At present, with the continuous promotion of the "dual carbon" strategy, the demand for carbon emission reduction in industries such as cement, steel, thermal power, and chemical industry has been increasing year by year. For the problem of carbon dioxide capture from low partial pressure gas sources, most of the capture methods adopted in large-scale capture projects are chemical absorption methods based on amine absorbents. Analyzing from both the current application of carbon capture projects and the progress of technical research, the wet carbon capture technology is still the bottom guarantee technology for achieving the "dual carbon" goal.

[0003] The organic amine method mainly involves the capture processes of absorption and regeneration in the process of capturing carbon dioxide. And the amount of energy consumption of the carbon dioxide capture system mainly depends on the steam consumption in the regeneration section. In the traditional regeneration process, the regenerated gas rich in high calorific value is directly cooled and condensed through a heat exchanger after leaving the regeneration tower, and its heat energy is wasted and not recycled by the system. Secondly, the heat exchange of the top condenser adopts the principle of wall heat exchange. Due to the existence of solid wall thermal resistance and fouling thermal resistance in the wall heat exchange process, there is a certain gap in the heat transfer efficiency of wall heat exchange compared with direct contact heat exchange. In addition, affected by aerosols and the vapor pressure properties of amines themselves, the escape of amines in the regenerated gas is inevitable. At the same time, most of the amine-based carbon capture devices only use the method of a gas-liquid separator (equipped with wire mesh) for the gas-liquid separation of the regenerated gas, and its effect is average. Therefore, there are indeed some amine-based carbon capture devices, and the carbon dioxide products obtained at the rear end carry the smell of organic amines. Summary of the Invention

[0004] The main purpose of the present invention is to provide a heat recovery process system for the regenerated gas of a wet decarbonization technology, aiming to solve the existing technical problems.

[0005] To achieve the above object, the present invention provides a heat recovery process system for the regenerated gas of a wet decarbonization technology, including an absorption unit, a rich and lean liquid heat exchange unit, and a regeneration unit connected in sequence; The regeneration unit includes a regeneration tower, in which a regeneration section for making the rich liquid contact the high-temperature steam reversely from bottom to top and a regenerated gas water washing system for forming a washing liquid circulation loop to transfer the calorific value in the regenerated gas to the washing liquid are provided in sequence; The regenerated gas water washing system includes a regenerated gas water washing section, a regenerated gas water washing tank, a regenerated gas washing pump, and a regenerated gas water washing cooler connected in sequence; A section of one-way metal pipeline is led out at the outlet of the regenerated gas washing pump to transport the washing condensate to the front end of the rich liquid pump in the rich and lean liquid heat exchange unit, so that the washing liquid is mixed with the rich liquid to increase the internal heat of the rich liquid flow.

[0006] Further, the absorption unit includes an absorption tower, which successively includes an absorption section for countercurrently contacting the carbon-containing gas with the lean liquid from bottom to top and a water washing system for forming a washing liquid circulation loop.

[0007] Further, the water washing system includes a purified gas water washing section, a washing tank, a washing pump, and a water washing cooler connected in sequence. Among them, a one-way metal pipeline is led out at the outlet of the washing pump to convey the condensate to the front end of the rich liquid pump.

[0008] Further, during the process of the regenerated gas water washing system for recovering the calorific value of the regenerated gas, the temperature of the circulating washing liquid is controlled by adjusting the circulating water volume of the regenerated gas water washing cooler, wherein the spraying temperature of the circulating washing liquid is controlled between 50 - 90°C.

[0009] Further, the washing flow rate of the washing liquid in contact with the regenerated gas is 30 - 120% of the rich liquid circulation volume.

[0010] Further, packings are provided in the absorption section and the regeneration section, and the absorbent added in the packings can be any one of organic amine absorbents, amino acid salt absorbents, phase change absorbents, and ionic liquid absorbents.

[0011] Further, the regeneration unit further includes a condensation separation system composed of a regenerated gas condenser and a gas-liquid separator. The inlet end of the regenerated gas condenser is connected to the regenerated gas outlet at the top of the regeneration tower through a one-way metal pipeline, and the outlet end is connected to the inlet of the gas-liquid separator.

[0012] Further, a one-way metal pipeline is led out from the liquid outlet of the gas-liquid separator to convey the condensed water to the regenerated gas water washing tank.

[0013] Further, the regeneration unit further includes a reboiler, which is connected to the regeneration tower in parallel through a one-way metal pipeline and is used to provide the heat required for desorbing the rich liquid.

[0014] Further, the rich and lean liquid heat exchange unit further includes a rich and lean liquid heat exchanger, a lean liquid cooler, and a lean liquid pump that form a rich and lean liquid circulation loop between the absorption unit and the regeneration unit with the rich liquid pump.

[0015] The beneficial effects of the present invention are embodied in: The present invention adopts the method of adding a regenerated gas water washing section to the upper part of the regeneration tower, and pre-cools the regenerated gas through the circulating spraying of the washing liquid, thereby reducing the water vapor content in the regenerated gas, and further reducing the heat carried out by the regenerated gas.

[0016] After the washing liquid in the circulating spray of the present invention obtains a part of the heat in the regeneration gas and has a temperature rise, a part of the washing liquid after the temperature rise is mixed with the rich liquid discharged from the absorption tower, which can, to a certain extent, increase the heat in the rich liquid flow. The heat of the regeneration gas is recycled in the system in the form of the washing liquid. Therefore, the overall regeneration energy consumption in the desorption process and the usage amount of the externally supplied steam can be reduced.

[0017] By directly contacting and exchanging heat between the washing liquid and the regeneration gas through spraying in the present invention, the heat exchange efficiency between the gas and the liquid can be improved, and the working load of the regeneration gas condenser can be reduced.

[0018] Through water washing and spraying in the present invention, the mass transfer and separation effect of gas-liquid contact can be strengthened, the carrying amount of organic amine in the regeneration gas can be reduced, and further the amine smell in the subsequent carbon dioxide product can be avoided, effectively reducing the operation loss of the organic amine solution.

[0019] If all the condensed liquids in the capture system are collected at the rich liquid, the alkalinity of the rich liquid can be reduced, which is beneficial to the full desorption of carbon dioxide. Description of the Drawings

[0020] Figure 1 is the overall process flow chart of the flue gas carbon capture section provided by the present invention; Figure 2 is the process flow chart of the absorption unit provided by the present invention; Figure 3 is the process flow chart of the rich and lean liquid heat exchange unit provided by the present invention; Figure 4 is the process flow chart of the regeneration unit provided by the present invention.

[0021] Reference numerals: 101, absorption tower; 102, water washing cooler; 103, washing tank; 104, washing pump; 201, rich and lean liquid heat exchanger; 202, lean liquid cooler; 203, rich liquid pump; 204, lean liquid pump; 301, regeneration tower; 302, reboiler; 303, regeneration gas water washing cooler; 304, regeneration gas washing pump; 305, regeneration gas water washing tank; 306, regeneration gas condenser; 307, gas-liquid separator. Detailed Embodiments

[0022] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Without conflict, the embodiments and the features in the embodiments in the present application can be combined with each other. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0023] Please refer toFigure 1 , the present invention provides a process system for heat recovery of the regeneration gas in a wet decarbonization technology, which includes an absorption unit, a rich and lean liquid heat exchange unit, and a regeneration unit; The absorption unit is a place where the carbon-containing gas contacts and reacts with the organic amine absorbent, forming a purified gas with less carbon and a rich liquid with a high load of carbon dioxide. After being treated by the purified gas water washing section, the temperature of the purified gas drops to a preset value and is discharged out of the system.

[0024] The rich and lean liquid heat exchange unit enables the rich liquid generated by the absorption unit to fully exchange heat with the lean liquid generated by the regeneration unit, increasing the temperature of the rich liquid and decreasing the temperature of the lean liquid, thereby realizing the recovery and utilization of the heat of the lean liquid.

[0025] The regeneration unit steam-heats and strips the rich liquid generated by the absorption unit, forming a lean liquid for circulation between absorption and regeneration and a regeneration gas with a high calorific value. After being treated by a gas-liquid separation device, the regeneration gas forms a heterogeneous carbon dioxide product gas and condensed water.

[0026] Furthermore, please refer to Figure 2 , the absorption unit includes an absorption tower 101, and the absorption tower 101 successively includes an absorption section for counter-current contact of the carbon-containing gas and the lean liquid from bottom to top and a water washing system for forming a washing liquid circulation loop.

[0027] It should be noted that the carbon-containing gas enters the inner cavity of the absorption section from the bottom of the absorption tower 101 and flows in the upward direction, while the lean liquid is sprayed downward into the inner cavity of the absorption section. Packing is provided in the absorption section, and the carbon-containing gas and the lean liquid are in counter-current contact and reaction, and mass transfer and heat transfer phenomena occur on the packing. After the reaction, the absorbent will be loaded with carbon dioxide to form a rich liquid, and the carbon-containing gas will form a purified gas with less carbon.

[0028] It should be noted that the absorbent can be selected from traditional organic amine absorbents represented by monoethanolamine, diethanolamine, N-methyldiethanolamine, hydroxyethyl ethylenediamine, etc., or amino acid salts such as potassium (sodium) glycinate, potassium (sodium) alaninate, phase change absorbents, ionic liquid absorbents, etc.

[0029] Furthermore, please refer to Figure 2 , the water washing system includes a purified gas water washing section, a water washing cooler 102, a washing tank 103, and a washing pump 104, which are connected to each other by metal pipes to form a washing liquid circulation loop; Specifically, for the purified gas water washing section, the purified gas water washing section is a place where the purified gas and the washing water sprayed from the upper part of the absorption tower 101 are in counter-current contact. The purified gas water washing section is located above the absorption section, and a liquid accumulation tray and a riser pipe are provided at the connection.

[0030] The liquid inlet of the washing tank 103 is connected to the bottom outlet end of the water washing section, and the liquid outlet is connected to the liquid inlet end of the washing pump 104. The washing tank 103 is used to store the washing water for circulation.

[0031] The liquid inlet of the washing pump 104 is connected to the outlet end of the washing tank 103, and the liquid outlet is connected to the liquid inlet end of the water washing cooler 102, which is used to drive the washing liquid to flow in the pipeline.

[0032] The liquid inlet of the water washing cooler 102 is connected to the outlet end of the washing pump 104, and the liquid outlet is connected to the liquid inlet end of the purified gas water washing section. The function of the water washing cooler 102 is to cool and reduce the temperature of the circulating washing liquid.

[0033] It should be noted that after the purified gas exits the absorption section, it has a relatively high temperature and carries a large amount of amine liquid. After the purified gas enters the purified gas water washing section through the riser pipe, it contacts the purified gas countercurrently from top to bottom by spraying washing water. The temperature of the purified gas decreases and is discharged out of the system, while the washing liquid accumulates on the liquid collecting tray.

[0034] It should be noted that according to the flow sequence of the washing liquid, the equipment passed through are the washing tank 103, the washing pump 104, and the water washing cooler 102. The washing liquid enters the washing tank 103 by gravity. The washing tank 103 has the functions of storing liquid and buffering. The washing liquid in the washing tank 103 is forced to circulate in the water washing system by the suction of the washing pump 104. The washing liquid enters the water washing cooler 102, and the temperature of the washing liquid is reduced to a preset value through indirect heat exchange by water cooling. The cooled washing liquid then flows back into the absorption tower 101 again.

[0035] It should be noted that the equipment in the water washing system is arranged and designed according to the flow direction of the washing liquid, and a closed-loop circuit is formed in series. The connections between the equipment are all connected by one-way metal pipe elements.

[0036] Preferably, a section of one-way metal pipe is led out at the outlet of the washing pump 104 to transport the condensate to the front end of the rich liquid pump 203. After the washing liquid is mixed with the rich liquid, the internal heat of the rich liquid flow can be increased, and the overall regeneration energy consumption in the desorption process can be reduced.

[0037] Further, please refer to Figure 3 , the rich and lean liquid heat exchange unit includes the rich and lean liquid heat exchanger 201, the lean liquid cooler 202, the rich liquid pump 203, and the lean liquid pump 204, which are all interconnected in the form of pipelines to form a rich and lean liquid circulation loop between the absorption unit and the regeneration unit.

[0038] Specifically, for the rich and lean liquid heat exchanger 201, the rich and lean liquid heat exchanger 201 is a component for heat exchange between the rich liquid generated by the absorption tower 101 and the lean liquid flowing out of the regeneration tower 301.

[0039] The liquid inlet of the lean liquid cooler 202 is connected to the outlet of the lean liquid pump 204, and the liquid outlet is connected to the lean liquid feed port end of the absorption tower 101. The function of the lean liquid cooler 202 is to further reduce the temperature of the lean liquid.

[0040] The inlet of the rich liquid pump 203 is connected to the bottom discharge port of the absorption tower 101, and the outlet of the rich liquid pump 203 is connected to the rich liquid inlet of the rich and lean liquid heat exchanger 201. The rich liquid pump 203 is used to drive the rich liquid to flow in the pipeline.

[0041] The inlet of the lean liquid pump 204 is connected to the lean liquid discharge port of the rich and lean liquid heat exchanger 201, and the outlet of the lean liquid pump 204 is connected to the lean liquid inlet of the lean liquid cooler 202. The rich liquid pump 203 is used to drive the lean liquid to flow in the pipeline.

[0042] The equipment in the rich and lean liquid heat exchange unit is interconnected in the form of metal pipelines to form a circulation loop for the rich and lean liquid between the absorption unit and the regeneration unit. The connection sequence between the equipment follows the flow direction of the rich and lean liquid.

[0043] It should be noted that the rich liquid flowing out from the bottom of the absorption tower 101 is forced to flow through the rich and lean liquid heat exchanger 201 by the rich liquid pump 203 and enter the regeneration unit. The lean liquid flowing out from the regeneration unit is forced to flow through the rich and lean liquid heat exchanger 201 by the lean liquid pump 204. The high-temperature lean liquid and the low-temperature rich liquid converge at the rich and lean liquid heat exchanger 201 for heat exchange. The lean liquid after heat exchange enters the lean liquid cooler 202 under the drive of the lean liquid pump 204 to be further cooled to a preset temperature and then flows into the absorption tower 101.

[0044] It should be noted that the rich liquid is the saturated absorbent, and the lean liquid is the unsaturated absorbent.

[0045] Furthermore, please refer to Figure 4 , the regeneration unit includes a regeneration tower 301, a reboiler 302, and a condensation separation system.

[0046] Specifically, the regeneration tower 301 includes a regeneration section and a reboiler gas washing system from bottom to top in sequence.

[0047] The regeneration section is a place where the rich liquid is sprayed from top to bottom and contacts the high-temperature steam generated by the reboiler 302 in a countercurrent manner. The rich liquid is heated and stripped to release carbon dioxide.

[0048] It should be noted that the rich liquid enters the regeneration section from the rich and lean liquid heat exchange unit, flows from top to bottom into the inside of the reboiler 302, and is heated to boiling by the external high-temperature steam through heat exchange in the reboiler 302. The water in the rich liquid vaporizes into steam. The steam has a stripping effect to reduce the partial pressure of carbon dioxide and release the carbon dioxide in the rich liquid. There are fillers in the regeneration tower 301, and mass transfer and heat transfer phenomena occur when the gas-liquid two-phase contacts on the fillers. After the rich liquid is stripped and desorbed, it forms unsaturated lean liquid and reboiler gas rich in water vapor and carbon dioxide.

[0049] Furthermore, the regeneration gas water washing system consists of a regeneration gas water washing section, a regeneration gas water washing tank 305, a regeneration gas washing pump 304, and a regeneration gas water washing cooler 303, which are connected to each other by metal pipes to form a washing liquid circulation loop.

[0050] Specifically, the regeneration gas water washing section is a place where the regeneration gas contacts the sprayed washing water in a countercurrent manner. The regeneration gas water washing section is located above the regeneration section, and a liquid accumulation tray and a riser pipe are provided at the connection.

[0051] The inlet of the regeneration gas water washing tank 305 is connected to the bottom outlet end of the regeneration gas water washing section, and the liquid outlet is connected to the liquid inlet end of the regeneration gas washing pump 304. The regeneration gas water washing tank 305 is used to store the washing water for circulation.

[0052] The inlet of the regeneration gas washing pump 304 is connected to the bottom outlet end of the regeneration gas water washing tank 305, and the liquid outlet is connected to the liquid inlet end of the regeneration gas water washing cooler 303. The regeneration gas washing pump 304 is used to drive the washing liquid to flow in the pipeline.

[0053] The liquid inlet of the regeneration gas water washing cooler 303 is connected to the outlet end of the regeneration gas washing pump 304, and the liquid outlet is connected to the liquid inlet end of the regeneration tower 301. The function of the regeneration gas water washing cooler 303 is to reduce the temperature of the washing liquid to a preset temperature.

[0054] The reboiler 302 is connected to the regeneration tower 301 through a one-way metal pipe and is used to provide the heat required for desorbing the rich liquid.

[0055] Specifically, the reboiler 302 is connected to the regeneration tower 301 in parallel through a one-way metal pipe.

[0056] It should be noted that the regeneration gas is rich in high-temperature water vapor in addition to the captured carbon dioxide. The latent heat value of the high-temperature steam is relatively high. After the regeneration gas enters the regeneration gas water washing section from the regeneration section through the riser pipe, the sprayed washing water contacts the regeneration gas countercurrently from top to bottom. The temperature of the regeneration gas decreases and is discharged to the condensation separation system, while the washing liquid accumulates on the liquid accumulation tray.

[0057] It should be noted that according to the flow sequence of the washing liquid, the equipment passed through is the regeneration gas water washing tank 305, the regeneration gas washing pump 304, and the regeneration gas water washing cooler 303. The washing liquid enters the regeneration gas water washing tank 305 by gravity. The regeneration gas water washing tank 305 has the functions of storing liquid and buffering. The washing liquid in the regeneration gas water washing tank 305 is driven by the suction of the regeneration gas washing pump 304 to circulate in the regeneration gas water washing system. The washing liquid enters the regeneration gas water washing cooler 303, and the temperature of the washing liquid is reduced to the preset value through indirect heat exchange by water cooling. The cooled washing liquid flows into the regeneration tower 301 again.

[0058] It should be noted that in the regeneration gas water washing system, the equipment is arranged and designed according to the flow direction of the washing liquid, and a closed-loop circuit is formed in series. The connection between the equipment is all connected by one-way metal pipeline components.

[0059] When the regeneration gas water washing system is in use, the temperature of the washing liquid at the outlet of the regeneration gas water washing cooler 303 is controlled by adjusting the flow rate of the circulating cooling water to reach the preset temperature, so as to change the temperature of the regeneration gas leaving the regeneration gas water washing section and achieve different effects of recovering heat value. The spraying temperature of the circulating washing liquid is generally between 50-90°C, preferably 65-80°C.

[0060] The washing flow rate of the washing liquid in contact with the regeneration gas is 30-120% of the rich liquid circulation amount, preferably 60-100%, more preferably 60-100%, and even more preferably 80-100%.

[0061] Preferably, a section of one-way metal pipeline is led out at the outlet of the regeneration gas washing pump 304 to transport the condensate to the front end of the rich liquid pump 203. After the washing liquid is mixed with the rich liquid, the internal heat of the rich liquid flow can be increased, and the overall regeneration energy consumption in the desorption process can be reduced.

[0062] Preferably, a section of one-way metal pipeline is led out at the liquid outlet of the gas-liquid separator 307 to transport the condensed water to the regeneration gas washing tank 103, and the heat value in the regeneration gas is transferred to the washing liquid in the form of gas-liquid conversion.

[0063] It should be noted that the position indicated by the front end of the rich liquid pump 203 is the position between the bottom rich liquid kettle of the absorption tower 101 and the bottom rich liquid outlet end and the liquid inlet of the rich liquid pump 203.

[0064] Furthermore, the condensation separation system mainly includes a regeneration gas condenser 306 and a gas-liquid separator 307; The regeneration gas condenser 306, the inlet end of the regeneration gas condenser 306 is connected to the regeneration gas outlet at the top of the regeneration tower 301 through a one-way metal pipeline, and its outlet is connected to the inlet of the gas-liquid separator 307. The regeneration gas condenser 306 is used to reduce the temperature of the regeneration gas.

[0065] The gas-liquid separator 307, the gas-liquid separator 307 is used to separate the product carbon dioxide gas and condensed water.

[0066] It should be noted that after the regeneration gas is discharged from the regeneration gas water washing section, it enters the regeneration gas condenser 306, and the temperature of the regeneration gas is further reduced, forming a heterogeneous flow of gaseous carbon dioxide and liquid condensate.

[0067] It should be noted that the gas-liquid separator 307 separates the above heterogeneous two-phase flow to form the product carbon dioxide gas and condensed water; a section of one-way metal pipeline is led out at the liquid outlet of the gas-liquid separator 307 to transport the condensed water to the regeneration gas washing tank 305.

[0068] To better demonstrate the beneficial effects of the present invention, the above carbon capture process system is now compared with the traditional carbon capture process system. Taking a 10,000-ton / year carbon dioxide capture project in a power plant as an example and using 20 wt% ethanolamine aqueous solution as the absorbent benchmark, the comparison results are shown in Table 1 below:

[0069] Table 1 The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it.

[0070] It should be noted that if there are directional indications such as up, down, left, right, front, and back in the embodiments of the present invention, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture as shown in the drawings. If the specific posture changes, the directional indications will also change accordingly.

[0071] In addition, if there are descriptions such as "first" and "second" in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, or solution B, or the solution where A and B are satisfied simultaneously. In addition, "a plurality" means more than two. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist.

[0072] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A heat recovery process system for the regeneration gas of a wet decarbonization technology, characterized in that: It includes an absorption unit, a lean-rich liquid heat exchange unit, and a regeneration unit connected in sequence; The regeneration unit includes a regeneration tower (301). Inside the regeneration tower (301), there are successively arranged from bottom to top a regeneration section for making the rich liquid contact the high-temperature steam in a countercurrent manner and a re-gas water washing system for forming a washing liquid circulation loop to transfer the heat value in the re-gas to the washing liquid; The re-gas water washing system includes a re-gas water washing section, a re-gas water washing tank (305), a re-gas washing pump (304), and a re-gas water washing cooler (303) connected in sequence; At the outlet of the re-gas washing pump (304), a one-way metal pipeline is led to convey the washing condensate to the front end of the rich liquid pump (203) in the lean-rich liquid heat exchange unit, so that the washing liquid is mixed with the rich liquid to increase the heat inside the rich liquid flow.

2. The heat recovery process system for the regeneration gas of the wet decarbonization technology according to claim 1, wherein: The absorption unit includes an absorption tower (101). The absorption tower (101) successively includes from bottom to top an absorption section for making the carbon-containing gas contact the lean liquid in a countercurrent manner and a water washing system for forming a washing liquid circulation loop.

3. The heat recovery process system for the regeneration gas of a wet decarbonization technology as described in claim 2, characterized in that: The water washing system includes a purified gas water washing section, a washing tank (103), a washing pump (104), and a water washing cooler (102) connected in sequence. Among them, at the outlet of the washing pump (104), a one-way metal pipeline is led to convey the condensate to the front end of the rich liquid pump (203).

4. A heat recovery process system for the regeneration gas of a wet decarbonization technology as described in claim 1, characterized in that: During the process of the re-gas water washing system recovering the heat value of the re-gas, the temperature of the circulating washing liquid is controlled by adjusting the circulating water volume of the re-gas water washing cooler (303), and the spraying temperature of the circulating washing liquid is controlled between 50 - 90 °C.

5. A heat recovery process system for the regeneration gas of a wet decarbonization technology according to claim 1, characterized in that: The washing flow rate of the washing liquid in contact with the re-gas is 30 - 120% of the rich liquid circulation volume.

6. The heat recovery process system for the regenerated gas of a wet decarbonization technology as described in claim 2, characterized in that: Packings are provided in the absorption section and the regeneration section, and the absorbent added in the packings can be any one of organic amine absorbents, amino acid salt absorbents, phase change absorbents, and ionic liquid absorbents.

7. A heat recovery process system for the regeneration gas of a wet decarbonization technology as described in claim 1, characterized in that: The regeneration unit further includes a condensation separation system composed of a re-gas condenser (306) and a gas-liquid separator (307). The inlet end of the re-gas condenser (306) is connected to the re-gas outlet at the top of the regeneration tower through a one-way metal pipeline, and the outlet end is connected to the inlet of the gas-liquid separator (307).

8. A heat recovery process system for the regenerated gas of a wet decarbonization technology according to claim 7, characterized in that: A one-way metal pipeline is led from the liquid outlet of the gas-liquid separator (307) to convey the condensed water to the re-gas water washing tank (305).

9. The heat recovery process system for the regeneration gas of the wet decarbonization technology according to claim 1, characterized in that: The regeneration unit further includes a reboiler (302), which is connected to the regeneration tower (301) in parallel through a one-way metal pipeline and is used to provide the heat required for the desorption of the rich liquid.

10. A heat recovery process system for the regenerated gas of a wet decarbonization technology as described in claim 1, characterized in that: The lean-rich liquid heat exchange unit further includes a lean-rich liquid heat exchanger (201), a lean liquid cooler (202), and a lean liquid pump (204) that form a lean-rich liquid flow circuit between the absorption unit and the regeneration unit with the rich liquid pump (203).

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