Flue gas low-temperature adsorption, regeneration and purification system for realizing remelting balance of nitrogen oxides

Abstract

The invention relates to the technical field of flue gas purification and discloses a flue gas low-temperature adsorption, regeneration and purification system for realizing return balance of nitrogen oxides, the flue gas low-temperature adsorption, regeneration and purification system comprises a boiler, an adsorption and regeneration device and a regeneration rich gas circulating pipe, the boiler comprises a boiler body and a flue, and a hearth is arranged in the boiler body; the flue is communicated with the hearth to discharge smoke in the hearth, and the hearth is provided with a first combustion area with the temperature larger than or equal to 700 DEG C. The adsorption regeneration equipment is connected with the flue of the boiler. The inlet end of the regeneration rich gas circulating pipe is connected with the flue gas adsorption regeneration equipment, and the outlet end of the regeneration rich gas circulating pipe is communicated with the first combustion area of the hearth, so that the regeneration rich gas is conveyed into the first combustion area of the hearth. According to the flue gas low-temperature adsorption, regeneration and purification system for realizing the return balance of the nitrogen oxides, disclosed by the embodiment of the invention, the content of NOx in the system cannot be continuously increased, the NOx balance is realized, the regeneration rich gas treatment process is simple, the cost is low, and the boiler runs safely.

Description

Technical Field

[0001] The invention relates to the technical field of flue gas purification, and in particular to a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance. Background Art

[0002] Coal-fired flue gas contains a large amount of nitrogen oxides that affect the environment and human health. In the relevant technology, adsorbents are usually used to purify coal-fired flue gas by adsorption, that is, high-temperature flue gas, usually 200°C, is passed into an adsorption tower filled with adsorbents, and the nitrogen oxides in the flue gas are adsorbed by the adsorbent. This adsorption is usually called high-temperature adsorption. High-temperature adsorption has a poor adsorption and purification effect on flue gas and cannot achieve near-zero emissions. In addition, the adsorbent that has adsorbed nitrogen oxides is transported to a regeneration tower for heating and desorption to achieve regeneration of the adsorbent. The regenerated adsorbent is returned to the adsorption tower for adsorption and purification of the flue gas. The nitrogen oxides in the regenerated rich gas generated by the desorption of the adsorbent need to be subsequently treated, resulting in a complicated subsequent treatment process and high treatment costs. Summary of the invention

[0003] The present invention is based on the inventor's discovery and understanding of the following facts and problems:

[0004] In order to overcome the problems of high-temperature adsorption, low-temperature adsorption technology for flue gas is proposed in the relevant technology, that is, firstly, the high-temperature flue gas is passed into a spray cooling tower for cooling, and the temperature is reduced to low-temperature flue gas below room temperature, for example, and then the low-temperature flue gas is input into the adsorption tower for low-temperature adsorption, and the adsorbent saturated with adsorption is sent to the regeneration tower for heating desorption regeneration, and the regenerated adsorbent is then sent back to the adsorption tower for recycling. In low-temperature adsorption, the adsorption capacity of the adsorbent is increased exponentially in a low-temperature environment, which greatly improves the adsorption purification rate compared with conventional high-temperature flue gas adsorption, and can achieve near-zero emission of flue gas.

[0005] In order to process the regenerated rich gas, the related art proposes to return the regenerated rich gas to the boiler for combustion, so as to simplify the subsequent processing procedures of the regenerated rich gas and reduce the processing cost of the regenerated rich gas. However, the inventors found that returning the regenerated rich gas to the boiler for combustion will cause the nitrogen oxide NOx content in the boiler and the flue gas to continue to increase, which not only leads to high NOx in the purified flue gas and poor purification effect, but also as the cycle proceeds, the nitrogen oxide content in the system will reach an overload state, thereby affecting the safety of boiler operation and even making the system unable to operate.

[0006] The inventors have realized that NOx in flue gas is divided into combustion NOx and thermal NOx. Combustion NOx refers to NOx generated by thermal decomposition and oxidation of nitrogen-containing compounds in the fuel during combustion, while thermal NOx refers to NOx generated by the reaction of nitrogen and oxygen in the air at high temperatures. NOx generated by coal-fired boilers during combustion generally consists of 70% combustion NOx and 30% thermal NOx. The inventors have realized that since combustion NOx is generated by nitrogen-containing compounds in the fuel during combustion, its generation is usually unavoidable. However, thermal NOx is generated by the reaction of nitrogen and oxygen in a high-temperature environment of the boiler. The generation of thermal NOx will lead to an increase in the nitrogen oxide content in the boiler flue gas. Therefore, the inventors have discovered that by suppressing the generation of thermal NOx in the boiler, the NOx content in the flue gas can be reduced, the flue gas purification effect can be improved, and near-zero emissions can be achieved. Moreover, the regenerated rich gas desorbed and regenerated by the adsorbent used for adsorption and purification of the flue gas can be returned to the boiler for combustion. The NOx content in the system will not continue to increase, thus achieving NOx balance. The regenerated rich gas treatment process is simple, the cost is low, and the boiler operation is safe.

[0007] To this end, the present invention proposes a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance, so as to reduce the cost of treating nitrogen oxides in the flue gas.

[0008] The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention comprises a boiler, an adsorption regeneration device and a regeneration rich gas circulation pipe, wherein the boiler comprises a furnace body and a flue, wherein the furnace body has a furnace, wherein the flue is connected to the furnace to discharge the flue gas in the furnace, wherein the furnace has a first combustion zone, wherein the temperature of the first combustion zone is greater than or equal to 700°C;

[0009] The adsorption regeneration equipment is connected to the flue of the boiler, and is used to cool the flue gas discharged from the flue to low-temperature flue gas below zero degrees, use adsorbent to adsorb and purify the low-temperature flue gas into clean flue gas, and heat the adsorbent saturated with adsorption to desorb the adsorbent saturated with adsorption to regenerate regenerated rich gas, and the desorbed and regenerated adsorbent is circulated for adsorption and purification of the low-temperature flue gas;

[0010] The inlet end of the regeneration rich gas circulation pipe is connected to the flue gas adsorption regeneration device and the outlet end of the regeneration rich gas circulation pipe is connected to the first combustion zone of the furnace to transport the regeneration rich gas to the first combustion zone of the furnace.

[0011] The flue gas low-temperature adsorption regeneration and purification system for realizing nitrogen oxide return balance in the embodiment of the present invention performs low-temperature adsorption on the flue gas under low temperature conditions, improves the adsorption purification efficiency, reduces the pollutant content in the flue gas after purification, and achieves near-zero emissions. Moreover, through the regeneration rich gas circulation pipe, the regeneration rich gas containing nitrogen oxides generated by the desorption and regeneration of the adsorbent is transported to the furnace of the furnace body, which simplifies the regeneration rich gas treatment process and reduces the treatment cost. Moreover, since the temperature of the first combustion zone is greater than or equal to 700°C, thermal NOx is easily formed in the first combustion zone. The nitrogen oxides in the regeneration rich gas are sent into the first combustion zone of the furnace through the regeneration rich gas circulation pipe, so that the nitrogen oxides in the first combustion zone are always maintained at a certain content value, thereby suppressing the generation of thermal NOx in the first combustion zone in the furnace and achieving nitrogen oxide balance, thereby greatly reducing the generation of thermal NOx during combustion in the furnace, further reducing the cost of treating nitrogen oxides, and the NOx content in the system will not continue to increase, achieving NOx balance, simple regeneration rich gas treatment process, low cost, and safe boiler operation.

[0012] Optionally, the temperature of the first combustion zone is 700° C.-1200° C. Setting the temperature of the first combustion zone to 700° C.-1200° C. can greatly improve the service life of the regeneration rich gas circulation pipe and prevent the outlet end of the regeneration rich gas circulation pipe from being above 1200° C. for a long time, resulting in a lower service life.

[0013] Optionally, the regeneration rich gas circulation pipe is arranged in the middle of the boiler in the height direction and is arranged horizontally. It can be understood that the middle of the boiler is generally the position with the highest temperature, and the amount of thermal NOx generated here is relatively large compared with other positions of the boiler. The regeneration rich gas circulation pipe is arranged in the middle of the boiler, so that the nitrogen oxides entering the regeneration rich gas circulation pipe can first enter the middle of the boiler for suppression, and then diffuse and suppress to the top and bottom of the boiler where the temperature is relatively low, which can greatly improve the suppression effect of thermal NOx.

[0014] Optionally, the outlet end of the regeneration rich gas circulation pipe is arranged adjacent to the edge of the furnace. This can prevent the outlet end of the regeneration rich gas circulation pipe from extending too deeply into the furnace and interfering with the normal combustion of the burner, which is beneficial to improving the combustion stability of the burner; at the same time, it can also prevent the regeneration rich gas circulation pipe from extending too far into the furnace, reducing the contact area between the regeneration rich gas circulation pipe and the combustion flame in the furnace, thereby reducing the heating temperature of the regeneration rich gas circulation pipe, which is further beneficial to improving the service life of the regeneration rich gas circulation pipe.

[0015] Optionally, there are multiple regeneration rich gas circulation pipes, and the outlet ends of the multiple regeneration rich gas circulation pipes are arranged at intervals on the furnace body. Nitrogen oxides can enter different positions in the first combustion zone through the multiple regeneration rich gas circulation pipes. Since the positions of the nitrogen oxides entering the first combustion zone are different, the nitrogen oxides entering the first combustion zone can have a larger diffusion area in the first combustion zone, which can fully suppress thermal NOx and is conducive to further improving the suppression effect of thermal NOx.

[0016] Optionally, the plurality of regeneration rich gas circulation pipes are divided into a plurality of groups, the plurality of groups of regeneration rich gas circulation pipes are arranged at intervals along the height direction of the furnace body, and each group of regeneration rich gas circulation pipes are arranged at intervals along the circumference of the furnace body.

[0017] The flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide return balance in an embodiment of the present invention divides a plurality of regeneration rich gas circulation pipes into a plurality of groups, and the plurality of groups of regeneration rich gas circulation pipes are spaced apart along the height direction of the furnace body, and each group of regeneration rich gas circulation pipes are spaced apart along the circumferential direction of the furnace body, which is beneficial to improving the uniformity of the distribution of nitrogen oxides in the first combustion zone, and further beneficial to improving the suppression effect on thermal NOx.

[0018] Optionally, the boiler includes a plurality of primary air ducts arranged at intervals in the height direction of the furnace body, and the outlet ends of at least some of the primary air ducts extend into the first combustion zone of the furnace. The outlet end of the regenerated rich gas circulation pipe is connected to at least some of the primary air ducts to transport the regenerated rich gas to the first combustion zone of the furnace through at least some of the primary air ducts.

[0019] The flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention returns nitrogen oxides to the first combustion zone of the furnace through the primary air duct, and there is no need to separately set up a regeneration rich gas circulation pipe on the furnace body to recycle the nitrogen oxides, so that the furnace body structure of the flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention is simple and easy to process and manufacture.

[0020] Optionally, the boiler includes a plurality of secondary air ducts arranged at intervals in the height direction of the furnace body, and the outlet ends of at least some of the secondary air ducts extend into the first combustion zone of the furnace. The outlet end of the regenerated rich gas circulation pipe is connected to at least some of the secondary air ducts to transport the regenerated rich gas to the first combustion zone of the furnace through at least some of the secondary air ducts.

[0021] The flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention returns nitrogen oxides to the first combustion zone of the furnace through the secondary air duct, and there is no need to separately set up a regeneration rich gas circulation pipe on the furnace body to recycle nitrogen oxides, so that the furnace body structure of the flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention is simple and easy to process and manufacture.

[0022] Optionally, the adsorption regeneration equipment includes a cooling device, an adsorption tower and a regeneration tower, the cooling device is connected to the flue, and is used to cool the flue gas discharged from the flue into low-temperature flue gas; the adsorption tower has a flue gas inlet and a clean flue gas outlet, the flue gas inlet is connected to the cooling device, the adsorption tower has an adsorbent, and is used to adsorb and purify the low-temperature flue gas into low-temperature clean flue gas; the regeneration tower is used to heat the adsorbent saturated with adsorption in the adsorption tower to desorb and regenerate it, the regeneration tower has a regeneration rich gas outlet for discharging the regeneration rich gas, and the regeneration rich gas outlet is connected to the inlet end of the regeneration rich gas circulation pipe.

[0023] The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention makes full use of the nitrogen oxide recycling generated in the boiler combustion flue gas to suppress the generation of thermal NOx in the furnace. There is no need to separately prepare nitrogen oxides and pass them into the boiler furnace, which can greatly reduce the manufacturing cost of nitrogen oxides, and further greatly reduce the cost of the flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention.

[0024] Optionally, the cooling device is a spray cooling tower, which has a smoke inlet for communicating with the flue and a smoke outlet for discharging the low-temperature flue gas, and the smoke outlet is connected to the flue gas inlet of the adsorption tower. When the temperature of the flue gas is low, the adsorption efficiency of the adsorbent can be greatly improved, which is beneficial to improve the flue gas treatment efficiency of the flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to an embodiment of the present invention.

[0026] Figure 2 It is a schematic structural diagram of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to an embodiment of the present invention.

[0027] Figure 3 It is a front view of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to an embodiment of the present invention.

[0028] Figure 4It is a cross-sectional view of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to an embodiment of the present invention.

[0029] Figure 5 It is a schematic structural diagram of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to another embodiment of the present invention.

[0030] Figure 6 It is a front view of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to another embodiment of the present invention.

[0031] Figure 7 It is a cross-sectional view of a boiler of a flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to another embodiment of the present invention.

[0032] Reference numerals:

[0033] 1. Boiler; 101. Furnace body; 1011. Furnace; 10111. First combustion zone; 102. Flue; 2. Regeneration rich gas circulation pipe; 3. Primary air duct; 4. Secondary air duct; 5. Adsorption tower; 501. Flue gas inlet; 502. Clean flue gas outlet; 6. Regeneration tower; 601. Regeneration rich gas outlet; 7. Spray cooling tower; 701. Smoke inlet; 702. Smoke outlet. DETAILED DESCRIPTION

[0034] Embodiments of the present invention 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 invention, but should not be understood as limiting the present invention.

[0035] The technical solution of the present application is described in detail below with reference to the accompanying drawings.

[0036] For example, Figures 1 to 7 As shown, the flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in an embodiment of the present invention includes a boiler 1, an adsorption regeneration device and a regeneration rich gas circulation pipe 2. The boiler 1 includes a furnace body 101 and a flue 102. The furnace body 101 has a furnace 1011. The flue 102 is connected to the furnace 1011 to discharge the flue gas in the furnace 1011. The furnace 1011 has a first combustion zone 10111, and the temperature of the first combustion zone 10111 is greater than or equal to 700°C.

[0037] The adsorption regeneration equipment is connected to the flue 102 of the boiler 1, and is used to cool the flue gas discharged from the flue 102 to low-temperature flue gas below zero degrees, use the adsorbent to adsorb and purify the low-temperature flue gas into clean flue gas, and heat the adsorbent saturated with adsorption to desorb the adsorbent saturated with adsorption to regenerate regenerated rich gas, and the desorbed and regenerated adsorbent is circulated for adsorption and purification of the low-temperature flue gas.

[0038] The inlet end of the regeneration rich gas circulation pipe 2 is connected to the adsorption regeneration equipment and the outlet end of the regeneration rich gas circulation pipe 2 is connected to the first combustion zone 10111 of the furnace 1011 to transport the regeneration rich gas to the first combustion zone 10111 of the furnace 1011.

[0039] It should be noted that the first condition for the generation of thermal NOx is high temperature, and the second condition is the presence of air and oxygen, and this reaction is a reversible reaction. Since the temperature in the furnace 1011 can reach more than 1200°C to heat the water-cooled wall of the boiler 1 for power generation, and the furnace 1011 of the boiler 1 needs to be introduced with primary and secondary air for combustion support, it is impossible to reduce the generation of thermal NOx by controlling the combustion temperature and nitrogen content in the furnace 1011. However, since the reaction of nitrogen and oxygen to generate thermal NOx is a reversible reaction, nitrogen oxides can be introduced into the area in the furnace 1011 of the boiler 1 that is prone to generate thermal NOx to suppress the generation of thermal NOx.

[0040] The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance in the embodiment of the present invention performs low-temperature adsorption on flue gas under low-temperature conditions, thereby improving the adsorption purification efficiency, reducing the pollutant content in the flue gas after purification, and achieving near-zero emissions. Moreover, the regeneration rich gas containing nitrogen oxides generated by desorption and regeneration of the adsorbent is transported to the furnace 1011 of the furnace body 101 through the regeneration rich gas circulation pipe 2, thereby simplifying the regeneration rich gas processing process and reducing the processing cost. Moreover, since the temperature of the first combustion zone 10111 is greater than or equal to 700°C, thermal NOx is easily formed in the first combustion zone 10111. The nitrogen oxides in the regenerated rich gas are sent into the first combustion zone 10111 of the furnace 1011 through the regenerated rich gas circulation pipe 2, so that the nitrogen oxides in the first combustion zone 10111 are always maintained at a certain content value, thereby suppressing the generation of thermal NOx in the first combustion zone 10111 in the furnace 1011 and achieving nitrogen oxide balance. This can greatly reduce the generation of thermal NOx during combustion in the furnace 1011, further reduce the cost of treating nitrogen oxides, and the NOx content in the system will not continue to increase, thereby achieving NOx balance, the regenerated rich gas treatment process is simple, the cost is low, and the boiler 1 operates safely.

[0041] In some embodiments, the adsorption regeneration equipment includes a cooling device, an adsorption tower 5 and a regeneration tower 6. The cooling device is connected to the flue 102, and is used to cool the flue gas discharged from the flue 102 into low-temperature flue gas. The adsorption tower 5 has a flue gas inlet 501 and a clean flue gas outlet 502, and the flue gas inlet 501 is connected to the cooling device. The adsorption tower 5 has an adsorbent for adsorbing and purifying the low-temperature flue gas into low-temperature clean flue gas. The regeneration tower 6 is used to heat the adsorbent saturated with adsorption in the adsorption tower 5 to desorb and regenerate it. The regeneration tower 6 has a regeneration rich gas outlet 601 for discharging regeneration rich gas, and the regeneration rich gas outlet 601 is connected to the inlet end of the regeneration rich gas circulation pipe 2.

[0042] For example, Figure 1 As shown, the flue gas discharged from the flue 102 of the boiler 1 is cooled to low-temperature flue gas by a cooling device and then enters the adsorption tower 5 through the flue gas inlet 501. The nitrogen oxides in the low-temperature flue gas entering the adsorption tower 5 are adsorbed by the adsorbent in the adsorption tower 5 and become clean flue gas and are discharged through the clean flue gas outlet 502. The adsorbent saturated with adsorption enters the regeneration tower 6 for desorption, and the desorbed adsorbent returns to the adsorption tower 5 for re-adsorption, and the regenerated rich gas generated by desorption is discharged through the regeneration rich gas outlet 601. The nitrogen oxides in the regeneration rich gas enter the regeneration rich gas circulation pipe 2 through the inlet end of the regeneration rich gas circulation pipe 2, and the nitrogen oxides entering the regeneration rich gas circulation pipe 2 enter the first combustion zone 10111 of the furnace 1011 through the outlet end of the regeneration rich gas circulation pipe 2.

[0043] In some embodiments, the cooling device is a spray cooling tower 7 , which has a smoke inlet 701 for communicating with the flue 102 and a smoke outlet 702 for discharging low-temperature smoke, and the smoke outlet 702 is connected to the smoke inlet 501 of the adsorption tower 5 .

[0044] For example, Figure 1 As shown, the flue gas discharged from the flue 102 enters the spray cooling tower 7 through the smoke inlet 701, is spray-cooled in the spray cooling tower 7, and then discharged through the smoke outlet 702, so that the temperature of the high-temperature flue gas is reduced to below zero degrees before entering the adsorption tower 5. By setting the cooling device as the spray cooling tower 7, the treatment efficiency of the high-temperature flue gas can be improved, and the cost is relatively low.

[0045] Optionally, the temperature of the first combustion zone 10111 is 700°C-1200°C.

[0046] It is understandable that the temperature of the furnace 1011 in the boiler 1 can sometimes reach above 1200°C. Since the inlet end of the regeneration rich gas circulation pipe 2 extends into the first combustion zone 10111 of the boiler 1, if the temperature range of the first combustion zone 10111 is set too high, the outlet end of the regeneration rich gas circulation pipe 2 is in the high temperature area for a long time for high temperature burning, and the regeneration rich gas circulation pipe 2 is prone to high temperature deformation. Therefore, setting the temperature of the first combustion zone 10111 to 700°C-1200°C can greatly improve the service life of the regeneration rich gas circulation pipe 2 and prevent the outlet end of the regeneration rich gas circulation pipe 2 from being above 1200°C for a long time, resulting in a lower service life.

[0047] In some embodiments, the regeneration rich gas circulation pipe 2 is disposed in the middle of the boiler 1 in the height direction and arranged horizontally.

[0048] For example, Figures 2 to 4 As shown, when installing the regeneration rich gas circulation pipe 2, a through hole can be first opened on the furnace wall of the furnace body 101, and then the inlet end of the regeneration rich gas circulation pipe 2 is extended into the furnace 1011 of the boiler 1, and the regeneration rich gas circulation pipe 2 is connected to the furnace body 101 by flange or welding, so that the regeneration rich gas circulation pipe 2 is easy to install. It can be understood that the middle of the boiler 1 is generally the position with the highest temperature, and the amount of thermal NOx generated here is relatively large compared with other positions of the boiler 1. The regeneration rich gas circulation pipe 2 is arranged in the middle of the boiler 1, so that the nitrogen oxides entering the regeneration rich gas circulation pipe 2 can first enter the middle of the boiler 1 for suppression, and then diffuse and suppress to the top and bottom of the boiler 1 where the temperature is relatively low, which can greatly improve the suppression effect of thermal NOx.

[0049] In some embodiments, the outlet end of the regeneration rich gas circulation pipe 2 is arranged adjacent to the edge of the furnace 1011 .

[0050] For example, Figure 4 As shown, the flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide return balance in the embodiment of the present invention can prevent the outlet end of the regeneration rich gas circulation pipe 2 from extending too deeply into the furnace 1011 and interfering with the normal combustion of the burner, which is beneficial to improving the combustion stability of the burner; at the same time, it can also prevent the regeneration rich gas circulation pipe 2 from extending too far into the furnace 1011, reducing the contact area between the regeneration rich gas circulation pipe 2 and the combustion flame in the furnace 1011, thereby reducing the heating temperature of the regeneration rich gas circulation pipe 2, which is further beneficial to improving the service life of the regeneration rich gas circulation pipe 2.

[0051] In some embodiments, there are multiple regeneration rich gas circulation pipes 2 , and the multiple regeneration rich gas circulation pipes 2 are arranged on the furnace body 101 at intervals.

[0052] For example, Figures 2 to 4 As shown, the flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycle balance in an embodiment of the present invention arranges multiple regeneration rich gas circulation pipes 2 at intervals on the furnace body 101. Nitrogen oxides can enter different positions in the first combustion zone 10111 through the multiple regeneration rich gas circulation pipes 2. Since the positions of the nitrogen oxides entering the first combustion zone 10111 are different, the nitrogen oxides entering the first combustion zone 10111 can diffuse over a larger area in the first combustion zone 10111, which can fully suppress thermal NOx, and is beneficial to further improve the suppression effect of thermal NOx.

[0053] Optionally, the plurality of regeneration rich gas circulation pipes 2 are divided into a plurality of groups, the plurality of groups of regeneration rich gas circulation pipes 2 are arranged at intervals along the height direction of the furnace body 101 , and each group of regeneration rich gas circulation pipes 2 are arranged at intervals along the circumference of the furnace body 101 .

[0054] For example, Figures 2 to 4 As shown, multiple regeneration rich gas circulation pipes 2 are divided into two groups. The two groups of regeneration rich gas circulation pipes 2 are spaced apart in the height direction of the furnace body 101. Each group of regeneration rich gas circulation pipes 2 includes eight regeneration rich gas circulation pipes 2. The eight regeneration rich gas circulation pipes 2 are evenly spaced apart along the circumference of the furnace body 101. Two regeneration rich gas circulation pipes 2 are provided on each furnace wall of the furnace body 101.

[0055] The flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide recycle balance in an embodiment of the present invention divides a plurality of regeneration rich gas circulation pipes 2 into a plurality of groups, and the plurality of groups of regeneration rich gas circulation pipes 2 are arranged at intervals along the height direction of the furnace body 101, and each group of regeneration rich gas circulation pipes 2 are arranged at intervals along the circumferential direction of the furnace body 101, which is beneficial to improving the uniformity of the distribution of nitrogen oxides in the first combustion zone 10111, and further beneficial to improving the suppression effect on thermal NOx.

[0056] In some embodiments, the flue gas low-temperature adsorption regeneration and purification system for achieving nitrogen oxide return balance according to the embodiments of the present invention includes a plurality of primary air ducts 3, and the plurality of primary air ducts 3 are arranged at intervals in the height direction of the furnace body 101, and the outlet ends of at least some of the primary air ducts 3 extend into the first combustion zone 10111 of the furnace 1011, and at least some of the primary air ducts 3 form a regeneration rich gas circulation pipe 2, and the nitrogen oxides are transported to the first combustion zone 10111 of the furnace 1011 through the primary air ducts 3.

[0057] At least part of the outlet ends of the primary air ducts 3 extend into the first combustion zone 10111 of the furnace 1011. It can be understood that part of the outlet ends of the primary air ducts 3 extend into the first combustion zone 10111 of the furnace 1011, or all of the outlet ends of the primary air ducts 3 extend into the first combustion zone 10111 of the furnace 1011.

[0058] For example, Figures 5 to 7As shown, nitrogen oxides enter the first combustion zone 10111 of the furnace 1011 through a portion of the primary air duct 3. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide return balance in the embodiment of the present invention returns nitrogen oxides to the first combustion zone 10111 of the furnace 1011 through the primary air duct 3, and there is no need to separately set a regeneration rich gas circulation pipe 2 on the furnace body 101 to return nitrogen oxides, so that the furnace body 101 of the flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide return balance in the embodiment of the present invention has a simple structure and is easy to manufacture.

[0059] In some embodiments, the boiler 1 includes a plurality of secondary air ducts 4 arranged at intervals in the height direction of the furnace body 101, and the outlet ends of at least some of the secondary air ducts 4 extend into the first combustion zone 10111 of the furnace 1011, and the outlet end of the regenerated rich gas circulation pipe 2 is connected to at least some of the secondary air ducts 4 to transport the regenerated rich gas to the first combustion zone 10111 of the furnace 1011 through at least some of the secondary air ducts 4.

[0060] For example, Figures 5 to 7 As shown, nitrogen oxides enter the first combustion zone 10111 of the furnace 1011 through part of the secondary air duct 4. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide return balance in the embodiment of the present invention returns nitrogen oxides to the first combustion zone 10111 of the furnace 1011 through the secondary air duct 4, and there is no need to separately set a regeneration rich gas circulation pipe 2 on the furnace body 101 to return nitrogen oxides, so that the furnace body 101 of the flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide return balance in the embodiment of the present invention has a simple structure and is easy to manufacture.

[0061] In other embodiments, nitrogen oxides may also enter the first combustion zone 10111 in the furnace 1011 through a portion of the primary air duct 3 and a portion of the secondary air duct 4.

[0062] In the description of the present invention, it is to 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”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0063] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0064] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0065] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature 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. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0066] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. 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 invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0067] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance, characterized in that: include: A boiler, the boiler comprising a furnace body and a flue, the furnace body having a furnace, the flue being connected to the furnace to discharge the flue gas in the furnace, the furnace having a first combustion zone, the temperature of the first combustion zone being greater than or equal to 700° C.; an adsorption regeneration device connected to the flue of the boiler, for cooling the flue gas discharged from the flue to low-temperature flue gas below zero degrees, purifying the low-temperature flue gas into clean flue gas by adsorption using an adsorbent, and heating the adsorbent saturated with adsorption to desorb the adsorbent saturated with adsorption to regenerate regenerated rich gas, and the desorbed and regenerated adsorbent is circulated for adsorption and purification of the low-temperature flue gas; and A regeneration rich gas circulation pipe, wherein the inlet end of the regeneration rich gas circulation pipe is connected to the adsorption regeneration device and the outlet end of the regeneration rich gas circulation pipe is connected to the first combustion zone of the furnace to transport the regeneration rich gas to the first combustion zone of the furnace.

2. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 1 is characterized in that: The temperature of the first combustion zone is 700°C-1200°C.

3. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 2 is characterized in that: The outlet end of the regeneration rich gas circulation pipe is arranged in the middle of the boiler in the height direction and is arranged horizontally.

4. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 1 is characterized in that: The outlet end of the regeneration rich gas circulation pipe is adjacent to the edge of the furnace.

5. The flue gas low temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 1 is characterized in that There are multiple regeneration rich gas circulation pipes, and the outlet ends of the multiple regeneration rich gas circulation pipes are arranged at intervals on the furnace body.

6. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 5 is characterized in that: The plurality of regeneration rich gas circulation pipes are divided into a plurality of groups, the plurality of groups of regeneration rich gas circulation pipes are arranged at intervals along the height direction of the furnace body, and each group of regeneration rich gas circulation pipes are arranged at intervals along the circumference of the furnace body.

7. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 1 is characterized in that: The boiler includes a plurality of primary air ducts arranged at intervals in the height direction of the furnace body, and the outlet ends of at least some of the primary air ducts extend into the first combustion zone of the furnace. The outlet end of the regenerated rich gas circulation pipe is connected to at least some of the primary air ducts to transport the regenerated rich gas to the first combustion zone of the furnace through at least some of the primary air ducts.

8. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 1 is characterized in that: The boiler includes a plurality of secondary air ducts arranged at intervals in the height direction of the furnace body, and the outlet ends of at least some of the secondary air ducts extend into the first combustion zone of the furnace. The outlet end of the regenerated rich gas circulation pipe is connected to at least some of the secondary air ducts to transport the regenerated rich gas to the first combustion zone of the furnace through at least some of the secondary air ducts.

9. The flue gas low temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to any one of claims 1 to 8, characterized in that: The adsorption regeneration equipment comprises: a cooling device, the cooling device being in communication with the flue and being used for cooling the flue gas discharged from the flue into low-temperature flue gas; an adsorption tower, the adsorption tower having a flue gas inlet and a clean flue gas outlet, the flue gas inlet being connected to the cooling device, the adsorption tower having an adsorbent therein for adsorbing and purifying the low-temperature flue gas into low-temperature clean flue gas; and A regeneration tower is used to heat the adsorbent saturated with adsorption in the adsorption tower to desorb and regenerate it. The regeneration tower has a regeneration rich gas outlet for discharging the regeneration rich gas, and the regeneration rich gas outlet is connected to the inlet end of the regeneration rich gas circulation pipe.

10. The flue gas low-temperature adsorption regeneration purification system for achieving nitrogen oxide recycling balance according to claim 9, characterized in that: The cooling device is a spray cooling tower, which has a smoke inlet for communicating with the flue and a smoke outlet for discharging the low-temperature smoke, and the smoke outlet is connected to the smoke inlet of the adsorption tower.

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