A system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas.

Abstract

The utility model relates to energy utilization technical field, concretely relates to a system of using high temperature CO2 desorption gas to handle thermal power plant wastewater, system includes: the evaporation tower, the first bottom entrance of evaporation tower is used to receive the gas that is greater than preset temperature and is produced to the adsorbent desorption carbon dioxide, first top entrance receives wastewater, and wastewater and gas counter current contact, first top outlet is used for discharging the mixed steam including the gas after cooling and the water vapor that wastewater vaporization produced, first bottom outlet is used for discharging the solid material that remains after wastewater vaporization. In the utility model, the high temperature waste heat of carbon dioxide desorption process is converted into the effective driving force of wastewater evaporation, and the cooling of carbon dioxide gas is realized simultaneously by using wastewater evaporation, the construction of the novel system of " carbon - water collaborative processing" is realized, and the limitation of one - way flow of energy in traditional technology is broken through. The energy level matching problem between high - grade heat energy and low - grade demand is solved.

Description

Technical Field

[0001] This utility model relates to the field of energy utilization technology, specifically to a system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas. Background Technology

[0002] In recent years, carbon capture, utilization, and storage (CCUS) technology has become a key pathway for the thermal power industry. Meanwhile, in addition to CO2 emissions, the treatment of high-salinity wastewater is also a significant environmental challenge during the operation of thermal power plants. Wastewater generated by thermal power plants mainly includes circulating cooling wastewater, desulfurization wastewater, and chemical water treatment wastewater. This wastewater has high salt content and complex composition, and traditional treatment methods such as evaporation and crystallization are energy-intensive. How to achieve low-cost, zero-discharge wastewater while improving the overall energy efficiency of the plant is a common problem faced by thermal power plants.

[0003] However, existing technologies utilize the waste heat from flue gas to heat the absorbent, thereby achieving desorption of the rich liquid. This waste heat is then used to heat the high-salinity wastewater, increasing its temperature before it enters the evaporator. This ensures the optimal reaction temperature between the absorbent and carbon dioxide while reducing the evaporation time of the wastewater within the evaporator, thus fully utilizing the system's heat. However, this method can only capture the low-temperature waste heat generated during the chemical absorption process of CO2, resulting in low utilization efficiency. Utility Model Content

[0004] In view of this, the present invention provides a system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas, in order to solve the problem of low utilization rate of the low-temperature waste heat generated during the CO2 capture process using only chemical absorption in the prior art.

[0005] The technical solution provided by this utility model is as follows:

[0006] In a first aspect, this utility model provides a system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas. The system includes an evaporation tower, which includes a first bottom inlet, a first top inlet, a first top outlet, and a first bottom outlet.

[0007] The first bottom inlet is used to receive gas generated by carbon dioxide desorption by the adsorbent at a temperature higher than a preset temperature. The first top inlet receives wastewater, and the wastewater and the gas are in countercurrent contact. The first top outlet is used to discharge a mixture of cooled gas and water vapor generated by the vaporization of the wastewater. The first bottom outlet is used to discharge the remaining solid matter after the wastewater vaporization.

[0008] In this invention, the high-temperature waste heat from the carbon dioxide desorption process is converted into an effective driving force for wastewater evaporation. Simultaneously, the evaporation of wastewater is used to cool the carbon dioxide gas, thus realizing the construction of a novel "carbon-water synergistic treatment" system, breaking through the limitations of unidirectional energy flow in traditional technologies. It solves the energy level matching problem between high-grade thermal energy (high-temperature gas) and low-grade demand (wastewater evaporation).

[0009] In an optional embodiment, the system further includes: a condenser, the condenser including a shell side, a tube side, a second bottom inlet, a third bottom inlet, a second bottom outlet, a second top outlet, and a third top outlet; the second bottom inlet is connected to the first top outlet and is used to receive the mixed vapor and transfer the mixed vapor to the shell side; the third bottom inlet is used to receive condensate and transfer the condensate to the tube side; the second top outlet is used to discharge carbon dioxide generated after the mixed vapor is condensed; the third top outlet is used to discharge condensate after the temperature rises; and the second bottom outlet is used to discharge liquid water generated after the mixed vapor is condensed.

[0010] In this invention, the condenser enables gas-liquid separation of the CO2 and water vapor mixture discharged from the evaporator, condensing the water vapor into liquid water. The purified CO2 is then easily recovered or stored. Simultaneously, the condensate can be demineralized water that has entered the boiler. The demineralized water absorbs the heat of condensation, raises its temperature, and then enters the boiler, achieving secondary utilization of waste heat. Furthermore, the condensate can be reused in the boiler, reducing water waste and meeting the requirements of zero wastewater discharge and cascade energy utilization in thermal power plants.

[0011] In an optional embodiment, the system further includes an adsorption tower and a desorption tower, the adsorption tower including a fourth bottom inlet, a fourth top outlet, and a fifth top outlet, and the desorption tower including a second top inlet and a sixth top outlet; the fourth bottom inlet is used to receive the flue gas to be treated and to capture carbon dioxide in the flue gas using a built-in adsorbent, the fourth top outlet is used to discharge the decarbonized flue gas, and the fifth top outlet is used to discharge the adsorbent after capturing carbon dioxide; the second top inlet is connected to the fifth top outlet and is used to receive the adsorbent after capturing carbon dioxide, and the sixth top outlet is connected to the first bottom inlet and is used to discharge the gas generated by the desorption of carbon dioxide in the desorption tower at a temperature higher than a preset temperature.

[0012] In an optional embodiment, the system further includes: a flue gas preheater, the flue gas preheater including a fifth bottom inlet, a third top inlet, a seventh top outlet and an eighth top outlet; the fifth bottom inlet is connected to the first top outlet and is used to receive the mixed steam, the third top inlet is used to receive the flue gas to be treated, the seventh top outlet is used to discharge the mixed steam after heat exchange with the flue gas, and the eighth top outlet is connected to the fourth bottom inlet and is used to discharge the flue gas to be treated after heat exchange with the mixed steam.

[0013] In this invention, a flue gas preheater is set up to preheat the flue gas to be treated, thereby adapting it to the working temperature range of the adsorbent, reducing the heating energy consumption of the adsorption tower, and at the same time, the waste heat of the mixed gas can be utilized, realizing the cascade utilization of energy.

[0014] In one alternative embodiment, the evaporation tower includes an atomizing device, or the system further includes an atomizing device for atomizing wastewater.

[0015] In this invention, by atomizing the wastewater, the contact area between the wastewater and the high-temperature gas can be maximized, the heat exchange efficiency can be improved, and the thermal energy of the high-temperature gas can be efficiently utilized.

[0016] In one optional embodiment, the system further includes a desulfurization tower, the desulfurization tower having a sixth bottom inlet and a ninth top outlet, the sixth bottom inlet being used to receive flue gas to be treated, and the ninth top outlet being used to discharge the desulfurized flue gas to be treated.

[0017] In this invention, a desulfurization tower is set up to remove sulfur dioxide, providing "clean flue gas" for the subsequent CO2 capture system (adsorption tower, desorption tower), ensuring the activity of the adsorbent and the stable operation of the equipment.

[0018] In one alternative embodiment, the temperature range of the gas received by the first bottom inlet is 850°C to 950°C.

[0019] In one alternative embodiment, the temperature of the mixed vapor discharged from the first top outlet ranges from 180°C to 220°C.

[0020] In one alternative embodiment, the particle size of the atomized wastewater is from 5 μm to 100 μm.

[0021] In one alternative embodiment, the temperature range of the heat-exchanged mixed steam discharged from the seventh top outlet is 100°C to 150°C.

[0022] In this invention, based on the temperature change of the gas, the heat energy in the gas is utilized in stages by evaporating wastewater with high-temperature gas, preheating flue gas with medium-temperature mixed steam, and recovering condensate at low temperature. Attached Figure Description

[0023] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a structural block diagram of a system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas, as described in this utility model embodiment. Detailed Implementation

[0025] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0026] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components; and they can refer to a wireless connection or a wired connection. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0028] Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0029] This utility model provides a system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas, such as... Figure 1 As shown, the system includes an evaporation tower 100, which includes a first bottom inlet 101, a first top inlet 102, a first top outlet 103, and a second top outlet 104. The first bottom inlet 101 is used to receive gas generated by desorption of carbon dioxide by an adsorbent at a temperature higher than a preset temperature. The first top inlet 102 receives wastewater, and the wastewater and the gas are in countercurrent contact. The first top outlet 103 is used to discharge a mixture of cooled gas and water vapor generated by the vaporization of the wastewater. The second top outlet 104 is used to discharge the remaining solid matter after the wastewater vaporization.

[0030] The adsorbent can be a high-temperature solid adsorbent, such as calcium-based, lithium-based, and alkali metal-based adsorbents. This adsorbent can efficiently capture CO2 from flue gas at around 600℃ and achieve CO2 desorption and regeneration at around 900℃. That is, the main component of the gas produced after desorption of carbon dioxide by the adsorbent at a temperature higher than the preset temperature is carbon dioxide. In related technologies, cooling towers are often used to directly cool the gas (e.g., to below 100℃) to meet subsequent compression or storage requirements. However, this process may result in the loss of approximately 85% of high-grade heat energy through the cooling system. Meanwhile, the wastewater received at the first top inlet can be high-salinity wastewater from a thermal power plant. In related technologies, mechanical steam recompression or multi-effect evaporation technology is often used to treat the wastewater, but the energy consumption of this process reaches 60-80 kWh / t of water, accounting for 3-5% of the power plant's auxiliary energy consumption.

[0031] Based on this, the system incorporates an evaporation tower, which facilitates countercurrent heat exchange between high-temperature gas and wastewater. This achieves both the utilization of the high-temperature waste heat from the gas and the evaporation and crystallization treatment of the wastewater. The evaporation tower requires materials that are resistant to high temperatures, high salt concentrations, and corrosion; for example, high-temperature alloys or corrosion-resistant, high-temperature stainless steel can be used. Furthermore, a porous guide plate can be installed inside the evaporation tower. Upon entry, the high-temperature gas is dispersed into multiple uniformly rising airflows through the inclined openings of the guide plate, preventing wall flow effects caused by an excessively large tower diameter. Simultaneously, a gas collection hood can be installed at the first top outlet to create a directional convergence of the mixed vapors; and a salt collection hopper can be installed at the first bottom outlet to collect discharged solids such as solid salt.

[0032] In this embodiment, the high-temperature waste heat from the carbon dioxide desorption process is converted into an effective driving force for wastewater evaporation. Simultaneously, the evaporation of wastewater is used to cool the carbon dioxide gas, thus realizing the construction of a novel "carbon-water synergistic treatment" system and breaking through the limitation of unidirectional energy flow in traditional technologies. This solves the energy level matching problem between high-grade thermal energy (900℃ CO2) and low-grade demand (wastewater evaporation).

[0033] In one optional embodiment, the evaporation tower includes an atomizing device, or the system further includes an atomizing device, for atomizing the wastewater. The particle size of the atomized wastewater is 5 μm to 100 μm. Specifically, by atomizing the wastewater, the contact area between the wastewater and the high-temperature gas can be maximized, improving heat exchange efficiency and achieving efficient utilization of the high-temperature gas's thermal energy. The atomization treatment can be implemented after the wastewater enters the evaporation tower, or it can be implemented using an additional atomizing device. If implemented inside the evaporation tower, atomizing nozzles can be arranged radially in layers at the top of the tower to ensure that water droplets cover the entire cross-section of the tower. The additional atomizing device can be implemented using structures found in related technologies, which will not be elaborated upon here.

[0034] In one alternative implementation, such as Figure 1 As shown, the system further includes: a desulfurization tower 200, an adsorption tower 300, and a desorption tower 400. The adsorption tower includes a fourth bottom inlet 301, a fourth top outlet 302, and a fifth top outlet 303. The desorption tower includes a second top inlet 401 and a sixth top outlet 402. The desulfurization tower 200 includes a sixth bottom inlet (not shown in the figure) and a ninth top outlet 201. The sixth bottom inlet is used to receive the flue gas to be treated, and the ninth top outlet 201 is used to discharge the flue gas to be treated after desulfurization. The fourth bottom inlet 301 is used to receive the flue gas to be treated and uses a built-in adsorbent to capture carbon dioxide in the flue gas. The fourth top outlet 302 is used to discharge the decarbonized flue gas, and the fifth top outlet 303 is used to discharge the adsorbent after capturing carbon dioxide. The second top inlet 401 is connected to the fifth top outlet 303 and is used to receive the adsorbent after capturing carbon dioxide. The sixth top outlet 402 is connected to the first bottom inlet 101 and is used to discharge the gas with a temperature higher than a preset temperature generated by the desorption of carbon dioxide in the desorption tower.

[0035] Specifically, the adsorption tower contains a high-temperature solid adsorbent capable of capturing carbon dioxide from the flue gas. After capturing the carbon dioxide, the adsorbent is desorbed in the desorption tower. The adsorption tower and desorption tower can employ structures from relevant technologies for carbon dioxide capture and desorption, which will not be elaborated upon here.

[0036] The flue gas to be treated may contain sulfur dioxide. If the flue gas is directly fed into the adsorption tower, it may react chemically with the high-temperature solid adsorbents such as calcium-based and lithium-based adsorbents (e.g., sulfur dioxide reacts with calcium-based adsorbents to form calcium sulfate), causing the adsorbents to become "poisoned" and inactive, losing their ability to capture CO2 and directly affecting CO2 capture efficiency. Simultaneously, if sulfur dioxide enters the subsequent desorption tower with the flue gas, it will exacerbate equipment corrosion at a high temperature of around 900℃, shortening the service life of core equipment such as the desorption tower and evaporation tower. Therefore, a desulfurization tower is installed to remove sulfur dioxide, providing "clean flue gas" for the subsequent CO2 capture system (adsorption tower and desorption tower), ensuring the activity of the adsorbents and the stable operation of the equipment.

[0037] In an optional embodiment, the system further includes: a flue gas preheater (not shown in the figure), the flue gas preheater including a fifth bottom inlet, a third top inlet, a seventh top outlet and an eighth top outlet; the fifth bottom inlet is connected to the first top outlet and is used to receive the mixed steam, the third top inlet is used to receive the flue gas to be treated, the seventh top outlet is used to discharge the mixed steam after heat exchange with the flue gas, and the eighth top outlet is connected to the fourth bottom inlet and is used to discharge the flue gas to be treated after heat exchange with the mixed steam.

[0038] Specifically, the adsorbent in the adsorption tower can efficiently capture CO2 from flue gas at around 600℃. Therefore, in this embodiment, a flue gas preheater is used to preheat the flue gas to be treated, thereby adapting it to the working temperature range of the adsorbent, reducing the heating energy consumption of the adsorption tower, and utilizing the waste heat of the mixed steam, achieving cascaded energy utilization. In this flue gas preheater, since the mixed steam and flue gas cannot directly contact each other (which would lead to inter-gas mixing), the flue gas preheater uses indirect heat exchange equipment, such as shell-and-tube or plate heat exchangers.

[0039] In one alternative implementation, such as Figure 1 As shown, the system further includes a condenser 500, which includes a shell side, a tube side, a second bottom inlet 501, a third bottom inlet 502, a second bottom outlet 503, a second top outlet 504, and a third top outlet 505. The second bottom inlet 501 is connected to the first top outlet 103 and is used to receive the mixed vapor and transfer the mixed vapor to the shell side. The third bottom inlet 502 is used to receive condensate and transfer the condensate to the tube side. The second top outlet 504 is used to discharge the carbon dioxide generated after the mixed vapor is condensed. The third top outlet 505 is used to discharge the condensate after the temperature rises. The second bottom outlet 503 is used to discharge the liquid water generated after the mixed vapor is condensed.

[0040] Specifically, this embodiment includes a condenser capable of recovering the mixed steam output from the evaporator or the mixed steam after heat exchange in the flue gas preheater. The condenser comprises a shell side and a tube side. The mixed steam passes through the shell side, and the condensate passes through the tube side. After heat exchange in the condenser, the mixed steam is condensed, and the water vapor in the mixed steam is condensed into liquid water. The remaining carbon dioxide in the mixed steam is discharged from the second top outlet. The condensate flowing into the tube side can be boiler demineralized water. This demineralized water enters the condenser and exchanges heat with the mixed steam to obtain demineralized water at a higher temperature. This demineralized water can then be fed back into the boiler to achieve waste heat utilization.

[0041] In one optional embodiment, the temperature range of the gas received at the first bottom inlet is 850°C to 950°C. The temperature range of the mixed steam discharged from the first top outlet is 180°C to 220°C. The temperature range of the heat-exchanged mixed steam discharged from the seventh top outlet is 100°C to 150°C. Thus, based on the temperature change of the gas, i.e., through high-temperature gas evaporation of wastewater → medium-temperature mixed steam preheating of flue gas → low-temperature condensate recovery, the cascade utilization of thermal energy in the gas is realized.

[0042] As a specific application embodiment of this utility model, such as Figure 1 As shown, this system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas includes: a desulfurization tower 200, a flue gas preheater, an adsorption tower 300, a desorption tower 400, an evaporation tower 100, and a condenser 500. The desulfurization tower 200 receives the flue gas to be treated, desulfurizes it, and then outputs it. The desulfurized flue gas enters the adsorption tower 300, where the adsorbent captures carbon dioxide. The decarbonized flue gas exits the adsorption tower and exits through a chimney 600. The saturated adsorbent exits the adsorption tower 300 and enters the desorption tower 400, where desorption occurs, releasing high-temperature carbon dioxide gas. This high-temperature carbon dioxide gas enters the evaporation tower 100, along with the atomized wastewater. The wastewater comes into countercurrent contact with the high-temperature carbon dioxide, instantly vaporizing. The vapor is discharged from the evaporation tower along with the carbon dioxide gas, and the remaining solids in the wastewater are also collected from the evaporation tower. The mixed steam, including water vapor and carbon dioxide, discharged from the evaporator 100 enters the condenser 500 and passes through the shell side. At the same time, the demineralized water that subsequently enters the boiler also enters the condenser 500 and passes through the tube side. The mixed steam and the demineralized water exchange heat in the condenser 500. The demineralized water with increased temperature is discharged from the condenser 500 and enters the boiler. The water vapor in the mixed steam after heat exchange condenses into liquid water, and the remaining carbon dioxide in the mixed steam is discharged separately.

[0043] In addition, when the mixed steam is discharged from the evaporator, it can first enter the flue gas preheater. At the same time, the flue gas to be treated after desulfurization also first enters the flue gas preheater. After exchanging heat with the flue gas and the temperature decreases, the mixed steam then enters the condenser. After exchanging heat with the mixed steam and the temperature increases, the flue gas then enters the adsorption tower.

[0044] As a specific application embodiment of this utility model, such as Figure 1 As shown, this system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas includes: a desulfurization tower 200, an adsorption tower 300, a desorption tower 400, an evaporation tower 100, and a condenser 500. The flue gas to be treated is drawn from the desulfurization tower 200 and enters the bottom of the adsorption tower 300, where CO2 is captured. The decarbonized flue gas is discharged from the top of the adsorption tower 300 and exits through a chimney. The saturated adsorbent is discharged from the top of the adsorption tower 300 and enters the top of the desorption tower 400, where desorption occurs, releasing high-temperature CO2 gas. High-temperature CO2 gas at approximately 900°C enters from the bottom of the evaporation tower 100, evaporates the wastewater, and the CO2 gas containing water vapor is discharged from the top of the evaporation tower 100, with the temperature reduced to approximately 200°C. Wastewater enters from the top of evaporator 100, atomizes (droplets approximately 5µm in diameter), and enters evaporator 100 where it comes into countercurrent contact with high-temperature CO2 gas, instantly vaporizing. The steam is discharged from the top of evaporator 100 along with the CO2 gas, while solid salt is discharged and collected from the bottom. The CO2 and water vapor from evaporator 100 are condensed in tubular condenser 500. CO2 and water vapor pass through the shell side, while condensate passes through the tube side. Through condensation, water vapor condenses into liquid water, CO2 is discharged and recovered from the top of the shell side, and condensate is discharged and collected from the bottom of the shell side for reuse in the boiler. The cooling water for condenser 500 can be demineralized water entering the boiler, flowing through the tube side, and exiting from the top. The demineralized water, after being heated, enters the boiler, achieving waste heat utilization.

[0045] While exemplary embodiments and their advantages have been described in detail, those skilled in the art can make various changes, substitutions, and modifications to these embodiments without departing from the spirit of this invention and the scope of protection defined by the appended claims. Such modifications and variations all fall within the scope defined by the appended claims. For other examples, those skilled in the art should readily understand that the order of process steps can be changed while remaining within the scope of protection of this invention.

[0046] Furthermore, the scope of application of this utility model is not limited to the processes, mechanisms, manufacturing methods, material compositions, means, methods, and steps of the specific embodiments described in the specification. From the disclosure of this utility model, those skilled in the art will readily understand that existing or future-developed processes, mechanisms, manufacturing methods, material compositions, means, methods, or steps that perform substantially the same function or achieve substantially the same results as the corresponding embodiments described in this utility model can be applied according to this utility model. Therefore, the appended claims of this utility model aim to include these processes, mechanisms, manufacturing methods, material compositions, means, methods, or steps within their scope of protection.

Claims

1. A system for treating wastewater from thermal power plants using high-temperature CO2 desorption gas, characterized in that, The system includes: an evaporation tower, the evaporation tower including a first bottom inlet, a first top inlet, a first top outlet and a first bottom outlet; The first bottom inlet is used to receive gas generated by carbon dioxide desorption by the adsorbent at a temperature higher than a preset temperature. The first top inlet receives wastewater, and the wastewater and the gas are in countercurrent contact. The first top outlet is used to discharge a mixture of cooled gas and water vapor generated by the vaporization of the wastewater. The first bottom outlet is used to discharge the remaining solid matter after the wastewater vaporization.

2. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 1, characterized in that, The system further includes a condenser, which includes a shell side, a tube side, a second bottom inlet, a third bottom inlet, a second bottom outlet, a second top outlet, and a third top outlet; The second bottom inlet is connected to the first top outlet and is used to receive the mixed vapor and transfer the mixed vapor to the shell side. The third bottom inlet is used to receive condensate and transfer the condensate to the tube side. The second top outlet is used to discharge the carbon dioxide generated after the mixed vapor is condensed. The third top outlet is used to discharge the condensate after the temperature rises. The second bottom outlet is used to discharge the liquid water generated after the mixed vapor is condensed.

3. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 1, characterized in that, The system further includes an adsorption tower and a desorption tower, the adsorption tower including a fourth bottom inlet, a fourth top outlet and a fifth top outlet, and the desorption tower including a second top inlet and a sixth top outlet; The fourth bottom inlet is used to receive the flue gas to be treated and to capture the carbon dioxide in the flue gas using a built-in adsorbent. The fourth top outlet is used to discharge the decarbonized flue gas, and the fifth top outlet is used to discharge the adsorbent after capturing carbon dioxide. The second top inlet is connected to the fifth top outlet and is used to receive the adsorbent after capturing carbon dioxide. The sixth top outlet is connected to the first bottom inlet and is used to discharge the gas generated by desorbing carbon dioxide in the desorption tower at a temperature higher than a preset temperature.

4. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 3, characterized in that, The system also includes a flue gas preheater, which includes a fifth bottom inlet, a third top inlet, a seventh top outlet, and an eighth top outlet; The fifth bottom inlet is connected to the first top outlet and is used to receive the mixed steam. The third top inlet is used to receive the flue gas to be treated. The seventh top outlet is used to discharge the mixed steam after heat exchange with the flue gas. The eighth top outlet is connected to the fourth bottom inlet and is used to discharge the flue gas to be treated after heat exchange with the mixed steam.

5. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 1, characterized in that, The evaporation tower includes an atomizing device, or the system further includes an atomizing device for atomizing wastewater.

6. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 3, characterized in that, The system also includes a desulfurization tower, which has a sixth bottom inlet and a ninth top outlet. The sixth bottom inlet is used to receive the flue gas to be treated, and the ninth top outlet is used to discharge the flue gas to be treated after desulfurization.

7. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 1, characterized in that, The temperature range of the gas received by the first bottom inlet is 850°C to 950°C.

8. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 1, characterized in that, The temperature range of the mixed gas discharged from the first top outlet is 180°C to 220°C.

9. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 5, characterized in that, The particle size of the wastewater after atomization treatment is 5μm to 100μm.

10. The system for treating thermal power plant wastewater using high-temperature CO2 desorption gas according to claim 4, characterized in that, The temperature range of the heat-exchanged mixed steam discharged from the seventh top outlet is 100°C to 150°C.

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