Low-temperature adsorption-regeneration purification system for flue gas

Abstract

A low-temperature adsorption-regeneration purification system for flue gas. The system comprises a spray cooling tower (1), an adsorption tower (2), a first heat exchanger (4), a regeneration tower (3) and a cold energy recovery assembly (6), wherein the spray cooling tower (1) is configured to cool flue gas introduced thereinto to low-temperature flue gas at sub-zero temperatures; the adsorption tower (2) is configured to adsorb and purify into clean flue gas the low-temperature flue gas discharged from the spray cooling tower; the first heat exchanger (4) is configured to exchange heat between the clean flue gas discharged through a flue gas outlet (22) and a first medium introduced through a first hot-side inlet (41) in the first heat exchanger (4); a regeneration section of the regeneration tower (3) is configured to heat an adsorbent to regenerate the adsorbent, while a cooling section (33) is configured to cool the regenerated adsorbent; and the cold energy recovery assembly (6) is configured to recover cold energy from the clean flue gas discharged from the adsorption tower (2) and / or cold energy from clean flue gas discharged through a first cold-side outlet (44). The low-temperature adsorption-regeneration purification system for flue gas can recover and utilize cold energy in flue gas multiple times, thereby reducing the consumption of other energy sources.

Description

Flue gas low-temperature adsorption regeneration purification system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 202410281168.8 and application date March 12, 2024, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present application relates to the technical field of flue gas purification, and in particular to a flue gas low-temperature adsorption regeneration purification system. Background Art

[0004] Low-temperature integrated pollutant removal technology is a comprehensive flue gas pollutant control technology. In this control technology, the adsorbent regeneration process in the regeneration tower often needs to maintain a high temperature (above 300°C) for a long time. After the adsorbent is regenerated, the adsorbent is quickly cooled down and reused so that the regenerated adsorbent can be passed into the adsorption tower for reuse. However, in related technologies, an electric refrigeration mechanism is generally used to obtain cooling capacity for cooling the adsorbent, which consumes a lot of energy and has high economic costs. Summary of the Invention

[0005] This application is based on the inventor's discovery and understanding of the following facts and problems:

[0006] Low-temperature pollutant integrated removal technology can reduce the flue gas temperature discharged from the boiler to below zero degrees Celsius, and can also remove dust, SO2, NO X The content is reduced to less than 1mg / Nm 3 That is to say, the flue gas discharged by the low-temperature integrated pollutant removal technology has a certain amount of cooling capacity. If it is not used, it will cause a waste of cooling capacity. In this application, the cooling section of the regeneration tower requires cooling capacity for cooling the cooling section. Among them, although the pollutant content in the flue gas is low, directly passing the flue gas into the cooling section of the regeneration tower will also have a certain impact on the pipeline equipment in the cooling section, making subsequent maintenance difficult. Therefore, clean air can be used for heat exchange with low-temperature flue gas, and then the clean air after heat exchange can be passed into the cooling section to ensure the stability of the overall operation of the system.

[0007] The present application aims to solve one of the technical problems in the related art at least to a certain extent.

[0008] To this end, this application proposes a flue gas low-temperature adsorption regeneration and purification system. This system utilizes heat exchange between air and low-temperature clean flue gas, using the heat-exchanged air to cool the adsorbent in the cooling section of the regeneration tower, thereby reusing the flue gas's cooling energy. Furthermore, a cooling energy recovery component can be used to recover the cooling energy from the low-temperature clean flue gas after heat exchange, thus avoiding waste of flue gas cooling energy.

[0009] The flue gas low-temperature adsorption regeneration purification system of this application includes:

[0010] A spray cooling tower, the spray cooling tower having a flue gas inlet and a flue gas outlet, and the spray cooling tower is used to cool the flue gas entering the tower to a sub-zero temperature;

[0011] An adsorption tower, the adsorption tower having a smoke inlet, a smoke outlet, an adsorbent inlet and an adsorbent outlet, the smoke inlet being connected to the smoke outlet, and being used for adsorbing and purifying the low-temperature smoke discharged from the spray cooling tower into clean smoke;

[0012] a first heat exchanger having a first hot side inlet, a first hot side outlet, a first cold side outlet, and a first cold side inlet connected to the smoke outlet, wherein the clean smoke discharged from the smoke outlet exchanges heat with the first medium introduced into the first hot side inlet in the first heat exchanger;

[0013] a regeneration tower, the regeneration tower comprising a regeneration section and a cooling section and having a regeneration inlet and a regeneration outlet, the regeneration section being used to heat an adsorbent to regenerate the adsorbent, the cooling section being connected to the first hot-side outlet to cool the regenerated adsorbent via a first medium discharged from the first hot-side outlet, the adsorbent inlet being connected to the regeneration outlet, and the adsorbent outlet being connected to the regeneration inlet to circulate the adsorbent between the adsorption tower and the regeneration tower;

[0014] A cold energy recovery component is connected to at least one of the smoke outlet of the adsorption tower and the first cold side outlet, so as to recover the cold energy in the clean flue gas discharged from the adsorption tower and / or the cold energy in the clean flue gas discharged from the first cold side outlet.

[0015] The flue gas low-temperature adsorption regeneration and purification system of this application utilizes a first heat exchanger to exchange heat between air and low-temperature clean flue gas. The heat-exchanged air is then passed into the cooling section of the regeneration tower to cool the adsorbent within the cooling section. The clean flue gas after heat exchange still has a certain amount of cold energy. This cold energy recovery component can be used to recycle the cold energy from the clean flue gas after heat exchange, further improving the flue gas cold energy recovery rate.

[0016] In some embodiments, the cold recovery component includes a cold recovery tower and a cold exchanger. The cold recovery tower is connected to the smoke outlet of the adsorption tower and the cold exchanger. The circulating liquid in the cold exchanger exchanges cold with the clean flue gas in the cooling recovery tower to recover the cold in the clean flue gas. The cold exchanger is connected to the spray cooling tower to indirectly cool the spray liquid discharged from the spray cooling tower and supply the cooled spray liquid to the spray cooling tower.

[0017] The flue gas low-temperature adsorption regeneration purification system of the present application can use the cold recovery component to recover the cold in the flue gas discharged from the smoke outlet of the adsorption tower, wherein the flue gas and the circulating liquid of the cold exchanger are sprayed for heat exchange in the cold recovery tower, and the circulating liquid after heat exchange is passed into the cold exchanger to exchange liquid with the spray liquid discharged from the spray cooling tower, thereby realizing the recovery and reuse of the flue gas cold.

[0018] In some embodiments, the spray cooling tower includes multiple spray components, and the spray cooling tower has multiple spray areas. The multiple spray areas are arranged in sequence along the flue gas flow direction in the spray cooling tower. The multiple spray components correspond to the multiple spray areas one by one. The cold exchanger is connected to at least one of the multiple spray areas to indirectly cool the spray liquid discharged from the at least one spray area and supply the cooled spray liquid to the spray component corresponding to the at least one spray area.

[0019] The flue gas low-temperature adsorption regeneration purification system of the present application can use the cold recovery component to recover the cold in the flue gas, and can use it again to cool the spray liquid discharged from the spray area, and then pass the cooled spray liquid into its corresponding spray area, thereby realizing the recovery and reuse of cold.

[0020] In some embodiments, the multiple spray areas include a primary spray area, a secondary spray area, a tertiary spray area, and a quaternary spray area arranged in sequence along the flue gas flow direction; the multiple spray assemblies include a primary spray assembly, a secondary spray assembly, a tertiary spray assembly, and a quaternary spray assembly; the cold exchanger is connected to the spray liquid outlet of the secondary spray area and the spray liquid inlet of the secondary spray assembly.

[0021] The flue gas low-temperature adsorption regeneration purification system of the present application divides the spray cooling tower into four spray zones, further optimizing the step-by-step cooling effect of the spray cooling tower, and avoiding excessive temperature differences between adjacent spray zones, which would result in excessive consumption of cooling capacity to cool the spray liquid.

[0022] In some embodiments, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a medium-temperature refrigerator and a low-temperature refrigerator. The medium-temperature refrigerator is connected to the spray liquid outlet of the three-stage spray assembly and the spray liquid inlet of the three-stage spray assembly, and is used to cool the spray liquid discharged from the spray liquid outlet of the three-stage spray assembly; the low-temperature refrigerator is connected to the spray liquid outlet of the four-stage spray assembly and the spray liquid inlet of the four-stage spray assembly, and is used to cool the spray liquid discharged from the spray liquid outlet of the four-stage spray assembly.

[0023] The flue gas low-temperature adsorption regeneration purification system of the present application can respectively utilize a medium-temperature refrigerator and a low-temperature refrigerator to cool the spray liquid in the third-stage spray zone and the spray liquid in the fourth-stage spray zone, so as to achieve step-by-step cooling of the flue gas in the spray cooling tower.

[0024] In some embodiments, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a cooling tower, the cooling water outlet of the cooling tower is connected to the cooling water inlet of the medium-temperature refrigerator and / or the cooling water inlet of the low-temperature refrigerator, and is used to cool the medium-temperature refrigerator and / or the low-temperature refrigerator.

[0025] The flue gas low-temperature adsorption regeneration purification system of the present application can use a medium-temperature refrigerator and a low-temperature refrigerator to cool the spray liquid discharged from the third-stage spray area and the fourth-stage spray area respectively, and will generate a certain amount of heat during use. Therefore, the flue gas low-temperature adsorption regeneration purification system of the present application can use a cooling water tower to cool the medium-temperature refrigerator and the low-temperature refrigerator respectively to ensure their safe operation.

[0026] In some embodiments, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a second heat exchanger, the second heat exchanger having a second hot side outlet, a second hot side inlet connected to the boiler flue, a second cold side inlet, a second hot side outlet connected to the flue gas inlet and a cold side outlet connected to the regeneration section. In the second heat exchanger, the second medium introduced into the second cold side inlet is supplied to the regeneration section after heat exchange with the flue gas discharged from the boiler flue.

[0027] The flue gas low-temperature adsorption regeneration purification system of the present application passes the flue gas discharged from the boiler flue into the second heat exchanger and exchanges heat with the second medium. The second medium after heat exchange is passed into the regeneration section of the regeneration tower to heat the adsorbent in the regeneration section, thereby realizing the reuse of the waste heat of the boiler flue gas.

[0028] In some embodiments, the regeneration tower further comprises a preheating section located above the regeneration section, and the second medium after heating the adsorbent in the regeneration section enters the preheating section to preheat the adsorbent in the preheating section.

[0029] The preheating section and heating section of the flue gas low-temperature adsorption regeneration purification system of the present application both adopt indirect heat exchange, which can not only avoid the mutual interference of high-temperature air or water vapor generated by the adsorbent during the cooling process, but also avoid impurities in the air from mixing into the adsorbent and affecting the adsorption effect of the adsorbent.

[0030] In some embodiments, the preheating section has a first discharge pipe and a first medium flow channel, the regeneration section has a second discharge pipe and a second medium flow channel, and the cooling section has a third discharge pipe and a third medium flow channel. The third medium flow channel is connected to the first hot side outlet to allow the cooled first medium to pass through. The cooled first medium is used to cool the adsorbent in the third discharge pipe. The second medium flow channel is connected to the second cold side outlet to allow the second medium after heat exchange to pass through. The second medium after heat exchange is used to heat the adsorbent in the second discharge pipe. The second medium flow channel is connected to the first medium flow channel so that the second medium after heating the adsorbent in the second discharge pipe passes into the first medium flow channel to preheat the adsorbent in the first discharge pipe.

[0031] The regeneration section of the flue gas low-temperature adsorption regeneration and purification system of this application can be heated using a second medium after heat exchange with the flue gas. The second medium, which has exchanged heat with the adsorbent in the regeneration section, can also be passed into the preheating section to preheat the adsorbent in the preheating section. The cooling section of the regeneration tower can utilize the low-temperature clean flue gas discharged from the adsorption tower for heat exchange, thereby cooling the adsorbent in the cooling section.

[0032] In some embodiments, the regeneration tower further comprises a transition section between the preheating section and the regeneration section and between the regeneration section and the cooling section, wherein the transition section comprises a suction port for extracting steam from the adsorbent.

[0033] During the preheating, heating, and cooling processes of the adsorbent in the flue gas low-temperature adsorption regeneration purification system of the present application, the adsorbent is affected by the varying temperatures, causing some vapor to precipitate. If not promptly discharged, this can cause the adsorbent to clump, hindering its flow. Therefore, the flue gas low-temperature adsorption regeneration purification system of the present application utilizes a suction port to promptly discharge the vapor generated in the adsorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a schematic structural diagram of the flue gas low-temperature adsorption regeneration purification system of the present application.

[0035] FIG2 is a schematic structural diagram of the regeneration tower of the flue gas low-temperature adsorption regeneration purification system of the present application.

[0036] FIG3 is a schematic cross-sectional view of the air-permeable housing of the flue gas low-temperature adsorption regeneration purification system of the present application.

[0037] Reference numerals: Breathable housing 100; Spray cooling tower 1; Flue gas inlet 11; Flue gas outlet 12; Primary spray zone 131; Secondary spray zone 132; Thirdary spray zone 133; Fourthary spray zone 134; Primary spray assembly 141; Secondary spray assembly 142; Thirdary spray assembly 143; Fourthary spray assembly 144; Adsorption tower 2; Smoke inlet 21; Smoke outlet 22; Adsorbent inlet 23; Adsorbent outlet 24; Regeneration tower 3; Preheating section 31; First discharge pipe 311; First medium flow channel 312; Heating section 32; Second discharge pipe 321; Second medium flow channel 322; Cooling section 33; Third discharge pipe 331; Third medium flow channel 332; Regeneration inlet 34; Regeneration outlet 35; First heat exchanger 4; First hot side inlet 41; First hot side outlet 42; First cold side inlet 43; First cold side outlet 44; Second heat exchanger 5; second hot side inlet 51; second hot side outlet 52; second cold side inlet 53; second cold side outlet 54; cold recovery assembly 6; cold recovery tower 61; cold exchanger 62; medium temperature refrigerator 7; low temperature refrigerator 8. DETAILED DESCRIPTION

[0038] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present application, but should not be understood as limiting the present application.

[0039] As shown in Figures 1 to 3, the flue gas low-temperature adsorption regeneration purification system of the present application includes: a spray cooling tower 1, an adsorption tower 2, a first heat exchanger 4, a regeneration tower 3 and a cold recovery component 6.

[0040] The spray cooling tower 1 has a flue gas inlet 11 and a flue gas outlet 12. The spray cooling tower 1 is used to cool the flue gas entering it to a low-temperature flue gas at a sub-zero temperature. The adsorption tower 2 has a flue gas inlet 21, a flue gas outlet 22, an adsorbent inlet 23, and an adsorbent outlet 24. The flue gas inlet 21 is connected to the flue gas outlet 12 and is used to adsorb and purify the low-temperature flue gas discharged from the spray cooling tower 1 into clean flue gas. The first heat exchanger 4 has a first hot side inlet 41, a first hot side outlet 42, a first cold side outlet, and a first cold side inlet 43 connected to the flue gas outlet 22. The clean flue gas discharged from the flue gas outlet 22 exchanges heat with the first medium introduced into the first hot side inlet 41 within the first heat exchanger 4.

[0041] In some embodiments, as shown in Figures 1 and 2, the boiler flue is connected to the flue gas inlet 11 of the spray cooling tower 1, so that the flue gas discharged from the boiler flue is passed into the spray cooling tower 1. The spray cooling tower 1 sprays and cools the flue gas entering the spray cooling tower until the flue gas is cooled to a sub-zero temperature. In the adsorption tower 2, the flue gas after adsorption and purification still has a certain amount of cooling capacity. Therefore, the clean flue gas discharged from the adsorption tower 2 is heat exchanged with the first medium in the first heat exchanger 4 to achieve flue gas cooling capacity recovery.

[0042] In some embodiments, the temperature of the low-temperature flue gas is -20°C to -15°C.

[0043] It should be noted that the first medium may be air, and the air is clean air after dust removal and purification.

[0044] It is understandable that the inventors found that when low-temperature flue gas (flue gas with a temperature below 0°C) is introduced into the adsorption tower 2, the adsorption effect of the low-temperature flue gas by the adsorbent in the adsorption tower 2 is better than the adsorption effect of the flue gas with a temperature above 0°C. Therefore, the use of the spray cooling tower 1 requires first cooling the flue gas and forming low-temperature flue gas so that the low-temperature flue gas can be better adsorbed and purified in the adsorption tower 2.

[0045] The regeneration tower 3 has a regeneration section and a cooling section 33 and has a regeneration inlet 34 and a regeneration outlet 35. The regeneration section is used to heat the adsorbent to regenerate the adsorbent. The cooling section 33 is connected to the first hot side outlet 42 to cool the regenerated adsorbent through the first medium discharged from the first hot side outlet 42. The adsorbent inlet 23 is connected to the regeneration outlet 35, and the adsorbent outlet 24 is connected to the regeneration inlet 34 to circulate the adsorbent between the adsorption tower 2 and the regeneration tower 3.

[0046] In some embodiments, as shown in Figures 1 and 2, the regeneration inlet 34 is used to receive the adsorbent after the adsorption tower 2 adsorbs and purifies the flue gas. After the adsorbent is heated, regenerated and cooled in the regeneration tower 3, it is sequentially passed into the adsorption tower 2 through the regeneration outlet 35 and the adsorbent inlet 23 to purify the flue gas in the adsorption tower 2 again.

[0047] The cold recovery component 6 is connected to at least one of the smoke outlet 22 and the first cold side outlet of the adsorption tower 2 to recover the cold in the clean flue gas discharged from the adsorption tower 2 and / or the cold in the clean flue gas discharged from the first cold side outlet.

[0048] It is understood that the cold recovery component 6 is capable of recovering cold from flue gas having a certain cold capacity. In some embodiments, the cold recovery component 6 is connected to both the smoke outlet 22 and the first cold-side outlet of the adsorption tower 2 to recover cold from the clean flue gas discharged from the adsorption tower 2 and the clean flue gas discharged from the first cold-side outlet.

[0049] The flue gas low-temperature adsorption regeneration and purification system of the present application utilizes the first heat exchanger 4 to exchange heat between air and low-temperature clean flue gas, and then passes the heat-exchanged air into the cooling section 33 of the regeneration tower 3 to cool the adsorbent within the cooling section 33. The clean flue gas after heat exchange still has a certain amount of cold energy, and the cold energy recovery component 6 can recycle the cold energy in the clean flue gas after heat exchange, further improving the flue gas cold energy recovery rate.

[0050] It should be noted that, as shown in FIG3 , the adsorbent can be filled inside the breathable shell 100 for adsorption. The adsorbent can be a granular or powdered adsorbent, or an adsorbent body made of powder or granular adsorbent, such as a spherical body or a cylinder formed by a powder or granular adsorbent through a binder. Of course, a protective shell can be further formed outside the adsorbent body, such as a breathable membrane covering the outside of the adsorbent body, to improve the strength of the adsorbent body. The breathable shell has air holes, and the flue gas can enter the breathable shell through the air holes. The flue gas can pass through the gaps between adjacent adsorbents and / or the holes of the adsorbent itself, thereby reducing not only the direct collision, friction and wear between the adsorbents, but also the generation of dust. The breathable shell can be in the shape of a rotating body such as a sphere or a cylinder, wherein the diameter of the breathable shell 100 is 10mm-100mm, and the diameter of the adsorbent is 1mm-10mm.

[0051] In some embodiments, as shown in Figure 1, the cold recovery component 6 includes a cold recovery tower 61 and a cold exchanger 62. The cold recovery tower 61 is connected to the smoke outlet 22 of the adsorption tower 2 and the cold exchanger 62. The circulating liquid in the cold exchanger 62 exchanges cold with the clean flue gas in the cooling recovery tower to recover the cold in the clean flue gas. The cold exchanger 62 is connected to the spray cooling tower 1 to indirectly cool the spray liquid discharged from the spray cooling tower 1 and supply the cooled spray liquid to the spray cooling tower 1.

[0052] It is understandable that the cold exchanger 62 is connected to the spray cooling tower 1, so as to cool the spray liquid discharged from the spray cooling tower 1. The circulating liquid with cold in the cold exchanger 62 is formed by direct heat exchange between the circulating liquid and the clean flue gas entering the cold recovery tower 61 in the cold recovery tower 61. Two pipelines can be arranged in the cold exchanger 62, one of which is used to pass the circulating liquid after heat exchange (temperature close to 0°C), and the other is used to pass the spray liquid discharged from the spray area after heat exchange with the flue gas (temperature higher than 0°C), so that indirect heat exchange can occur in the cold exchanger 62, so that the spray liquid can be used again in the spray area after heat exchange in the cold exchanger 62, thereby realizing cold recovery and reuse of the flue gas.

[0053] The flue gas low-temperature adsorption regeneration purification system of the present application can utilize the cold recovery component 6 to recover the cold in the flue gas discharged from the smoke outlet 22 of the adsorption tower 2, wherein the flue gas and the circulating liquid of the cold exchanger 62 are sprayed for heat exchange in the cold recovery tower 61, and the circulating liquid after heat exchange is passed into the cold exchanger 62 to carry out liquid-to-liquid heat exchange with the spray liquid discharged from the spray cooling tower 1, thereby realizing the recovery and reuse of the flue gas cold.

[0054] In some embodiments, as shown in Figure 1, the spray cooling tower 1 includes multiple spray components, and there are multiple spray areas in the spray cooling tower 1. The multiple spray areas are arranged in sequence along the flue gas flow direction in the spray cooling tower 1. The multiple spray components correspond to the multiple spray areas one by one. The cold exchanger 62 is connected to at least one of the multiple spray areas to indirectly cool the spray liquid discharged from the at least one spray area and supply the cooled spray liquid to the spray component corresponding to the at least one spray area.

[0055] It is understood that by using multiple spray assemblies and multiple spray zones to spray and cool the flue gas multiple times, the temperature of the flue gas in the spray cooling tower 1 can be gradually reduced. Since the amount of spray liquid required increases when the difference between the flue gas temperature and the spray liquid temperature is large, dividing the spray cooling tower 1 into multiple spray zones can avoid a large amount of consumption of the cooled spray liquid, thereby achieving a better cooling effect.

[0056] The flue gas low-temperature adsorption regeneration purification system of the present application can use the cold recovery component 6 to recover the cold in the flue gas, and can use it again to cool the spray liquid discharged from the spray area, and then pass the cooled spray liquid into its corresponding spray area, thereby realizing the recovery and reuse of cold.

[0057] In some embodiments, the plurality of spray areas include a primary spray area 131, a secondary spray area 132, a tertiary spray area 133 and a quaternary spray area 134 arranged in sequence along the direction of flue gas flow; the plurality of spray assemblies include a primary spray assembly 141, a secondary spray assembly 142, a tertiary spray assembly 143 and a quaternary spray assembly 144; the cold exchanger 62 is connected to the spray liquid outlet of the secondary spray area 132 and the spray liquid inlet of the secondary spray assembly 142.

[0058] That is, the secondary spray assembly 142 cools the flue gas to 30°C-35°C, and the clean flue gas in the adsorption tower 2 cools the spray liquid in the secondary spray zone 132 from 40°C-44°C to 30°C-34°C. In some embodiments, the clean flue gas in the adsorption tower 2 exchanges heat with the circulating liquid in the cold recovery tower 61 in the cold recovery tower 61, and the circulating liquid after heat exchange is then used to exchange heat with the spray liquid in the secondary spray zone 132 in the cold exchanger 62, so that the spray liquid in the secondary spray zone 132 is cooled from 40°C-44°C to 30°C-34°C.

[0059] It can be understood that after the flue gas enters the spray cooling tower 1, it flows in a bottom-to-top direction, that is, after the flue gas enters the spray cooling tower 1, it passes through the first-level spray area 131, the second-level spray area 132, the third-level spray area 133 and the fourth-level spray area 134 in sequence. Since the initial temperature of the flue gas (80℃-100℃) is relatively high, the flue gas can be spray-cooled by using the first-level spray component 141 spray liquid in the first-level spray area 131 using a normal temperature liquid. At this time, the temperature of the spray liquid in the first-level spray component 141 rises to 50℃-54℃. Since the temperature of the spray liquid is relatively high, it directly exchanges heat with the circulating liquid of the cold recovery tower 61. The heat exchange temperature difference is large, which will lead to poor heat exchange effect and easily cause a certain amount of energy waste. In some embodiments, the flue gas purification system of the present application also includes a water cooler, which is connected between the spray liquid outlet of the first-level spray area 131 and the liquid inlet of the first-level spray assembly 141. The spray liquid discharged from the first-level spray area 131 is cooled by the water cooler and returned to the first-level spray assembly 141.

[0060] The flue gas low-temperature adsorption regeneration purification system of the present application divides the spray cooling tower 1 into four spray zones, further optimizing the step-by-step cooling effect of the spray cooling tower 1, and avoiding excessive temperature differences between adjacent spray zones, which would result in excessive consumption of cooling capacity to cool the spray liquid.

[0061] In some embodiments, as shown in Figure 1, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a medium-temperature refrigerator 7 and a low-temperature refrigerator 8. The medium-temperature refrigerator 7 is connected to the spray liquid outlet of the three-stage spray assembly 143 and the spray liquid inlet of the three-stage spray assembly 143, and is used to cool the spray liquid discharged from the spray liquid outlet of the three-stage spray assembly 143; the low-temperature refrigerator 8 is connected to the spray liquid outlet of the four-stage spray assembly 144 and the spray liquid inlet of the four-stage spray assembly 144, and is used to cool the spray liquid discharged from the spray liquid outlet of the four-stage spray assembly 144.

[0062] That is to say, the flue gas low-temperature adsorption regeneration purification system of the present application can respectively use the medium-temperature refrigerator 7 and the low-temperature refrigerator 8 to cool the spray liquid in the third spray area 133 and the spray liquid in the fourth spray area 134 to achieve step-by-step cooling of the flue gas in the spray cooling tower 1.

[0063] In some embodiments, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a cooling tower (not shown in the figure), the cooling water outlet of the cooling tower is connected to the cooling water inlet of the medium-temperature refrigerator 7 and / or the cooling water inlet of the low-temperature refrigerator 8, and is used to cool the medium-temperature refrigerator 7 and / or the low-temperature refrigerator 8.

[0064] It can be understood that the flue gas low-temperature adsorption regeneration purification system of the present application can use the medium-temperature refrigerator 7 and the low-temperature refrigerator 8 to cool the spray liquid discharged from the third-level spray area 133 and the fourth-level spray area 134 respectively, and will generate a certain amount of heat during use. Therefore, the flue gas low-temperature adsorption regeneration purification system of the present application can use the cooling water tower to cool the medium-temperature refrigerator 7 and the low-temperature refrigerator 8 respectively to ensure their safe operation.

[0065] In some embodiments, as shown in Figure 1, the flue gas low-temperature adsorption regeneration purification system of the present application also includes a second heat exchanger 5, the second heat exchanger 5 has a second hot side outlet 52, a second hot side inlet 51 connected to the boiler flue, a second cold side inlet 53, a second hot side outlet 52 connected to the flue gas inlet 11 and a cold side outlet connected to the regeneration section. In the second heat exchanger 5, the second medium introduced into the second cold side inlet 53 is supplied to the regeneration section after heat exchange with the flue gas discharged from the boiler flue.

[0066] That is to say, the flue gas low-temperature adsorption regeneration purification system of the present application passes the flue gas discharged from the boiler flue into the second heat exchanger 5, and exchanges heat with the second medium. The second medium after heat exchange is passed into the regeneration section of the regeneration tower 3 to heat the adsorbent in the regeneration section, thereby realizing the reuse of the waste heat of the boiler flue gas.

[0067] In some embodiments, the regeneration tower 3 further comprises a preheating section 31 located above the regeneration section. The second medium after heating the adsorbent in the regeneration section enters the preheating section 31 to preheat the adsorbent in the preheating section 31 .

[0068] It is understood that the first medium exchanges heat with the low-temperature flue gas in the first heat exchanger 4. After heat exchange, the first medium is passed into the cooling section 33 to cool the adsorbent in the cooling section 33. The second medium exchanges heat with the high-temperature flue gas (flue gas discharged from the boiler flue) in the second heat exchanger 5. After heat exchange, the second medium is passed into the regeneration section to heat the adsorbent in the regeneration section. The second medium, after heat exchange with the adsorbent in the regeneration section, can be passed into the preheating section 31 to preheat the adsorbent in the preheating section 31.

[0069] The preheating section 31 and the heating section 32 of the flue gas low-temperature adsorption regeneration purification system of the present application both adopt an indirect heat exchange method, which can not only avoid the mutual interference of high-temperature air or water vapor generated by the adsorbent during the cooling process, but also avoid impurities in the air from mixing into the adsorbent and affecting the adsorption effect of the adsorbent.

[0070] In some embodiments, as shown in Figure 2, the preheating section 31 has a first discharge pipe 311 and a first medium flow channel 312, the regeneration section has a second discharge pipe 321 and a second medium flow channel 322, and the cooling section 33 has a third discharge pipe 331 and a third medium flow channel 332. The third medium flow channel 332 is connected to the first hot side outlet 42 to allow the cooled first medium to pass in. The cooled first medium is used to cool the adsorbent in the third discharge pipe 331. The second medium flow channel 322 is connected to the second cold side outlet 54 to allow the second medium after heat exchange to pass in. The second medium after heat exchange is used to heat the adsorbent in the second discharge pipe 321. The second medium flow channel 322 is connected to the first medium flow channel 312 so that the second medium after heating the adsorbent in the second discharge pipe 321 passes into the first medium flow channel 312 to preheat the adsorbent in the first discharge pipe 311.

[0071] In some embodiments, the first medium flow channel 312, the second medium flow channel 322 and the third medium flow channel 332 in the flue gas low-temperature adsorption regeneration purification system of the present application are all serpentine flow channels, which ensure the flow time of the heat exchange medium in the first medium flow channel 312, the second medium flow channel 322 and the third medium flow channel 332, thereby improving the heat exchange effect with the adsorbent.

[0072] The regeneration section of the flue gas low-temperature adsorption regeneration purification system of the present application can be heated by the second medium after heat exchange with the flue gas. The second medium after heat exchange with the adsorbent in the regeneration section can also be passed into the preheating section 31 to preheat the adsorbent in the preheating section 31. The cooling section 33 of the regeneration tower 3 can utilize the low-temperature clean flue gas discharged from the adsorption tower 2 for heat exchange to cool the adsorbent in the cooling section 33.

[0073] In some embodiments, the regeneration tower 3 further comprises a transition section between the preheating section 31 and the regeneration section and between the regeneration section and the cooling section 33 , wherein the transition section comprises a suction port for extracting steam from the adsorbent.

[0074] During the preheating, heating, and cooling processes of the adsorbent in the flue gas low-temperature adsorption regeneration purification system of the present application, the adsorbent is affected by the varying temperatures, causing some vapor to precipitate. If not promptly discharged, this can cause the adsorbent to clump, hindering its flow. Therefore, the flue gas low-temperature adsorption regeneration purification system of the present application utilizes a suction port to promptly discharge the vapor generated in the adsorbent.

[0075] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0076] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. Throughout the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0077] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0078] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0079] In this application, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples without contradiction.

[0080] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and cannot be understood as limitations on the present application. Changes, modifications, substitutions and variations of the above embodiments made by ordinary technicians in this field are all within the scope of protection of the present application.

Claims

1. A flue gas low-temperature adsorption regeneration purification system, comprising: A spray cooling tower, the spray cooling tower having a flue gas inlet and a flue gas outlet, and the spray cooling tower is used to cool the flue gas entering the tower to a sub-zero temperature; An adsorption tower, the adsorption tower having a smoke inlet, a smoke outlet, an adsorbent inlet and an adsorbent outlet, the smoke inlet being connected to the smoke outlet, and being used for adsorbing and purifying the low-temperature smoke discharged from the spray cooling tower into clean smoke; a first heat exchanger having a first hot side inlet, a first hot side outlet, a first cold side outlet, and a first cold side inlet connected to the smoke outlet, wherein the clean smoke discharged from the smoke outlet exchanges heat with the first medium introduced into the first hot side inlet in the first heat exchanger; a regeneration tower, the regeneration tower comprising a regeneration section and a cooling section and having a regeneration inlet and a regeneration outlet, the regeneration section being used to heat an adsorbent to regenerate the adsorbent, the cooling section being connected to the first hot-side outlet to cool the regenerated adsorbent via a first medium discharged from the first hot-side outlet, the adsorbent inlet being connected to the regeneration outlet, and the adsorbent outlet being connected to the regeneration inlet to circulate the adsorbent between the adsorption tower and the regeneration tower; A cold energy recovery component is connected to at least one of the smoke outlet of the adsorption tower and the first cold side outlet, so as to recover the cold energy in the clean flue gas discharged from the adsorption tower and / or the cold energy in the clean flue gas discharged from the first cold side outlet.

2. The flue gas low-temperature adsorption regeneration purification system according to claim 1, wherein: The cold recovery component includes a cold recovery tower and a cold exchanger. The cold recovery tower is connected to the smoke outlet of the adsorption tower and the cold exchanger. The circulating liquid in the cold exchanger exchanges cold with the clean flue gas in the cooling recovery tower to recover the cold in the clean flue gas. The cold exchanger is connected to the spray cooling tower to indirectly cool the spray liquid discharged from the spray cooling tower and supply the cooled spray liquid to the spray cooling tower.

3. The flue gas low-temperature adsorption regeneration purification system according to claim 2, wherein: The spray cooling tower includes multiple spray components, and there are multiple spray areas in the spray cooling tower. The multiple spray areas are arranged in sequence along the flue gas flow direction in the spray cooling tower. The multiple spray components correspond to the multiple spray areas one by one. The cold exchanger is connected to at least one of the multiple spray areas to indirectly cool the spray liquid discharged from the at least one spray area and supply the cooled spray liquid to the spray component corresponding to the at least one spray area.

4. The flue gas low-temperature adsorption regeneration purification system according to claim 3, wherein: The multiple spray areas include a primary spray area, a secondary spray area, a tertiary spray area and a quaternary spray area arranged in sequence along the direction of the flue gas flow; The plurality of spray assemblies include a primary spray assembly, a secondary spray assembly, a tertiary spray assembly and a quaternary spray assembly; The cold exchanger is connected to the spray liquid outlet of the secondary spray zone and the spray liquid inlet of the secondary spray assembly.

5. The flue gas low-temperature adsorption regeneration purification system according to claim 4, further comprising a medium-temperature refrigerator and a low-temperature refrigerator, wherein the medium-temperature refrigerator is connected to the spray liquid outlet and the spray liquid inlet of the three-stage spray assembly and is used to cool the spray liquid discharged from the spray liquid outlet of the three-stage spray assembly; The low-temperature refrigerator is connected to the spray liquid outlet and the spray liquid inlet of the four-stage spray assembly to cool the spray liquid discharged from the spray liquid outlet of the four-stage spray assembly.

6. The flue gas low-temperature adsorption regeneration purification system according to claim 5 further includes a cooling tower, wherein the cooling water outlet of the cooling tower is connected to the cooling water inlet of the medium-temperature refrigerator and / or the cooling water inlet of the low-temperature refrigerator, and is used to cool the medium-temperature refrigerator and / or the low-temperature refrigerator.

7. The flue gas low-temperature adsorption regeneration purification system according to any one of claims 1 to 6, further comprising a second heat exchanger, the second heat exchanger having a second hot side outlet, a second hot side inlet connected to the boiler flue, a second cold side inlet, a second hot side outlet connected to the flue gas inlet, and a cold side outlet connected to the regeneration section. In the second heat exchanger, the second medium introduced into the second cold side inlet exchanges heat with the flue gas discharged from the boiler flue and is then supplied to the regeneration section.

8. The flue gas low-temperature adsorption regeneration purification system according to claim 7, wherein: The regeneration tower further comprises a preheating section located above the regeneration section, and the second medium after heating the adsorbent in the regeneration section enters the preheating section to preheat the adsorbent in the preheating section.

9. The flue gas low-temperature adsorption regeneration purification system according to claim 8, wherein: The preheating section has a first feed pipe and a first medium flow channel, the regeneration section has a second feed pipe and a second medium flow channel, and the cooling section has a third feed pipe and a third medium flow channel. The third medium flow channel is connected to the first hot side outlet to allow the cooled first medium to pass through. The cooled first medium is used to cool the adsorbent in the third discharge pipe. The second medium flow channel is connected to the second cold side outlet to allow the second medium after heat exchange to pass through. The second medium after heat exchange is used to heat the adsorbent in the second discharge pipe. The second medium flow channel is connected to the first medium flow channel so that the second medium after heating the adsorbent in the second discharge pipe passes into the first medium flow channel to preheat the adsorbent in the first discharge pipe.

10. The flue gas low-temperature adsorption regeneration purification system according to claim 9, wherein: The regeneration tower further comprises a transition section between the preheating section and the regeneration section and between the regeneration section and the cooling section, wherein the transition section comprises a suction port for sucking steam from the adsorbent.

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