Flue gas low-temperature adsorption regeneration system capable of balancing nitrogen oxide circulation and remelting

Abstract

The invention relates to the technical field of flue gas purification, and discloses a flue gas low-temperature adsorption and regeneration system with balanced nitrogen oxide circulating and returning, the system comprises a boiler, a regeneration rich gas circulating pipe, an adsorption tower, a regeneration tower and a chemical reaction device, the boiler comprises a boiler body and a flue, the boiler body is provided with a hearth, and the flue is communicated with the hearth; the regeneration rich gas circulating pipe is arranged on the furnace body, and the outlet end of the regeneration rich gas circulating pipe extends into the hearth; the adsorption tower is provided with a flue gas inlet and a clean flue gas outlet, an alkaline reactant is arranged in the chemical reaction device, and the chemical reaction device is respectively communicated with the regenerated rich gas outlet and the inlet end of the regenerated rich gas circulating pipe. Excessive nitric oxide in the system partially reacts to generate by-products through the chemical reaction device, the content of nitric oxide in the whole system can be greatly reduced, it can be guaranteed that the content of nitric oxide in the whole system cannot reach the overload state, and the operation safety of the boiler is improved.

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 system for nitrogen oxide recycling and furnace balance. Background Art

[0002] In the related art, the flue gas generated by the combustion of coal-fired boilers contains a large amount of nitrogen oxide pollutants. In order to treat these nitrogen oxide pollutants, the adsorbent in the adsorption tower is usually used to adsorb the flue gas at high temperature (the temperature of the flue gas entering the adsorption tower is usually 200°C). The clean flue gas after adsorption is discharged from the adsorption tower, and the adsorbent saturated with adsorption is transported to the regeneration tower for desorption and regeneration to generate regeneration rich gas containing nitrogen oxides. The regeneration rich gas containing a large amount of nitrogen oxides generated in the regeneration tower needs further treatment. However, high-temperature adsorption has poor adsorption and purification effect on flue gas, and it is impossible to achieve near-zero emissions. In addition, the subsequent treatment process of nitrogen oxides in the regeneration rich gas generated by adsorbent desorption is complicated and the treatment cost is high. Summary of the invention

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

[0004] Related technologies have proposed low-temperature adsorption technology for flue gas, that is, firstly, high-temperature flue gas is passed into a spray cooling tower to cool down to low-temperature flue gas, and then the low-temperature flue gas is input into an adsorption tower for low-temperature adsorption, and the adsorbent saturated with adsorption is sent to a regeneration tower for heating desorption and 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 to conventional high-temperature flue gas adsorption, and can achieve near-zero flue gas emissions.

[0005] In order to deal with the nitrogen oxides in the regenerated rich gas desorbed in the regeneration tower, the related art proposes to return the regenerated rich gas to the boiler for combustion, so as to simplify the subsequent processing steps 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 content in the boiler and the flue gas to continue to increase, which will not only lead 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. 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] However, the inventors further realized that when the content of nitrogen oxides returning to the boiler exceeds a certain amount, a part of the nitrogen oxides is used for combustion and to suppress the formation of thermal NOx, while the other excess nitrogen oxides will cause a burden on the operation of the boiler. The excess nitrogen oxides cannot be absorbed by the boiler combustion, which will affect the operating safety of the boiler.

[0008] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a flue gas low-temperature adsorption regeneration system with high operating safety and nitrogen oxide recycling balance.

[0009] The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to the embodiment of the present invention comprises a boiler, an adsorption regeneration device, a chemical reaction 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, and the flue is connected to the furnace;

[0010] 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;

[0011] The chemical reaction device is provided with an alkaline reactant, and the chemical reaction device is respectively connected to the adsorption regeneration device and the inlet end of the regeneration rich gas circulation pipe, and is used for reacting and absorbing part of the nitrogen oxides discharged from the regeneration rich gas outlet;

[0012] The inlet end of the regeneration rich gas circulation pipe is connected to the chemical reaction device and the outlet end of the regeneration rich gas circulation pipe extends into the furnace, which is used to absorb and react part of the nitrogen oxides discharged from the regeneration rich gas outlet and then transport them to the furnace.

[0013] In the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance of the embodiment of the present invention, during operation, the flue gas discharged from the flue of the boiler enters the adsorption regeneration device, and the flue gas is adsorbed at low temperature 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. The nitrogen oxides in the regenerated rich gas generated in the adsorption regeneration device enter the chemical reaction device, and the stored alkaline reactant reacts with part of the nitrogen oxides to generate salt byproducts, realizing resource utilization, and the nitrogen oxides that are not absorbed and reacted enter the furnace through the regenerated rich gas circulation pipe, part of which is used for combustion, and part of which is used to inhibit the generation of thermal NOx. Therefore, after the excess nitrogen oxides generated by the desorption and regeneration of the adsorbent in the system are partially absorbed and reacted by the chemical reaction device, while effectively ensuring that the nitrogen oxides can be recycled for combustion and inhibit the generation of thermal NOx, it can also ensure that the nitrogen oxide content in the entire system will not reach an overload state, so that the nitrogen oxide content in the entire system is maintained in a dynamic balance, thereby improving the operating safety of the boiler.

[0014] Optionally, the furnace has a first combustion zone, the temperature of the first combustion zone is greater than or equal to 700°C, and the outlet end of the regeneration rich gas circulation pipe extends into the first combustion zone of the furnace, and is used to transport nitrogen oxides to the first combustion zone of the furnace. By extending the outlet end of the regeneration rich gas circulation pipe into the first combustion zone of the furnace, nitrogen oxides can enter 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, thereby greatly reducing the generation of thermal NOx during combustion in the furnace, and further greatly reducing the cost of treating nitrogen oxides.

[0015] Optionally, the temperature of the first combustion zone is 700℃-1200℃. Since the inlet end of the regeneration rich gas circulation pipe extends into the first combustion zone of the boiler, if the temperature range of the first combustion zone is set too high, the outlet end of the regeneration rich gas circulation pipe will be in the high temperature area for a long time for high temperature burning, and the regeneration rich gas circulation pipe is prone to high temperature deformation. Therefore, setting the temperature of the first combustion zone to 700℃-1200℃ 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℃ for a long time, resulting in a lower service life.

[0016] Optionally, the regeneration rich gas circulation pipe is arranged in the middle of the boiler and is arranged horizontally. It is understandable 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 thermal NOx suppression effect.

[0017] 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.

[0018] Optionally, there are multiple regeneration rich gas circulation pipes, and the multiple regeneration rich gas circulation pipes are arranged at intervals on the furnace body. 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, which is conducive to further improving the suppression effect of thermal NOx.

[0019] 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. This 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.

[0020] 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.

[0021] The flue gas low-temperature adsorption regeneration system for recycling and balancing nitrogen oxides 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 set a separate 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 system for recycling and balancing nitrogen oxides in the embodiment of the present invention is simple and easy to process and manufacture.

[0022] 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.

[0023] The flue gas low-temperature adsorption regeneration system for recycling and balancing nitrogen oxides 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 set a separate regeneration rich gas circulation pipe on the furnace body to return nitrogen oxides, so that the furnace body structure of the flue gas low-temperature adsorption regeneration system for recycling and balancing nitrogen oxides in the embodiment of the present invention is simple and easy to process and manufacture.

[0024] Optionally, the adsorption regeneration equipment comprises a spray cooling tower, an adsorption tower and a regeneration tower, the spray cooling tower has a smoke inlet for supplying smoke into the spray cooling tower and a smoke outlet for discharging cooled smoke, and the smoke inlet is connected to the flue;

[0025] The adsorption tower has a flue gas inlet and a clean flue gas outlet, the flue gas inlet is connected to the spray cooling tower, and the adsorption tower has an adsorbent for adsorbing and purifying the low-temperature flue gas into low-temperature clean flue gas;

[0026] The regeneration tower is used to heat the saturated adsorbent 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of a flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to an embodiment of the present invention.

[0028] Figure 2 It is a schematic diagram of a boiler of a flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to an embodiment of the present invention.

[0029] Figure 3 yes Figure 2 sectional view of .

[0030] Figure 4 It is a schematic diagram of a boiler of a flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to an embodiment of the present invention.

[0031] Figure 5 yes Figure 4 sectional view of .

[0032] Reference numerals:

[0033] 1. Boiler; 101. Furnace body; 1011. Furnace; 10111. First combustion zone; 102. Flue; 2. Regeneration rich gas circulation pipe; 3. Adsorption tower; 301. Flue gas inlet; 302. Clean flue gas outlet; 4. Regeneration tower; 401. Regeneration rich gas outlet; 5. Chemical reaction device; 6. Primary air duct; 7. Secondary air duct; 8. Spray cooling tower; 801. Smoke inlet; 802. 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] like Figures 1 to 5 As shown, the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance in an embodiment of the present invention includes a boiler 1, an adsorption regeneration device, a chemical reaction device 5 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.

[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 chemical reaction device 5 is provided with an alkaline reactant, and is connected to the adsorption regeneration device and the inlet end of the regeneration rich gas circulation pipe 2 respectively, for reacting and absorbing part of the nitrogen oxides discharged from the regeneration rich gas outlet 401 .

[0039] The inlet end of the regeneration rich gas circulation pipe 2 is connected to the chemical reaction device 5 and the outlet end of the regeneration rich gas circulation pipe 2 extends into the furnace 1011, which is used to absorb and react part of the nitrogen oxides discharged from the regeneration rich gas outlet 401 and then transport them to the furnace 1011.

[0040] For example, Figures 1 to 4As shown, the flue gas discharged from the flue 102 of the boiler 1 enters the adsorption regeneration device, and the flue gas is adsorbed at low temperature under low temperature conditions, which improves the adsorption purification efficiency, reduces the pollutant content in the flue gas after purification, and achieves near-zero emissions. The nitrogen oxides in the regenerated rich gas generated in the adsorption regeneration device enter the chemical reaction device 5, and the stored alkaline reactant reacts with part of the nitrogen oxides to generate salt by-products, realizing resource utilization. The nitrogen oxides that are not absorbed and reacted enter the furnace 1011 through the regenerated rich gas circulation pipe 2, part of which is used for combustion, and part of which is used to inhibit the generation of thermal NOx. Therefore, after the excess nitrogen oxides generated by the desorption and regeneration of the adsorbent in the system are partially absorbed and reacted by the chemical reaction device 5, while effectively ensuring that the nitrogen oxides can be returned to the furnace for combustion and inhibiting the generation of thermal NOx, it can also ensure that the nitrogen oxide content in the entire system will not reach an overload state, so that the nitrogen oxide content in the entire system is maintained in a dynamic balance, thereby improving the operating safety of the boiler 1.

[0041] In some embodiments, the furnace 1011 has a first combustion zone 10111, the temperature of the first combustion zone 10111 is greater than or equal to 700°C, and the outlet end of the regeneration rich gas circulation pipe 2 extends into the first combustion zone 10111 of the furnace 1011, and is used to transport nitrogen oxides to the first combustion zone 10111 of the furnace 1011.

[0042] It should be noted that the first condition for the generation of thermal NOx is high temperature, 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 above 0°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.

[0043] It is understandable that, 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 outlet end of the regeneration rich gas circulation pipe 2 is extended into the first combustion zone 10111 in the furnace 1011, so that nitrogen oxides can enter the first combustion zone 10111 in the furnace 1011 through the regeneration rich gas circulation pipe 2, so that the nitrogen oxides in the first combustion zone 10111 are always maintained at a certain content value, so as to suppress the generation of thermal NOx in the first combustion zone 10111 in the furnace 1011, thereby greatly reducing the generation of thermal NOx during combustion in the furnace 1011, and further greatly reducing the cost of treating nitrogen oxides, and the generated flue gas is discharged through the flue 102.

[0044] Optionally, the temperature of the first combustion zone 10111 is 700°C-1200°C.

[0045] 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.

[0046] Optionally, the regeneration rich gas circulation pipe 2 is disposed in the middle of the boiler 1 in the height direction and arranged horizontally.

[0047] For example, Figure 2 and Figure 3 As shown, when installing the regenerated 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 air intake 2 is extended into the furnace 1011 of the boiler 1, and the regenerated rich gas circulation pipe 2 is connected to the furnace body 101 by means of a flange or welding, so that the regenerated rich gas circulation pipe 2 is easy to install.

[0048] It can be understood that the middle part of the boiler 1 is generally the location with the highest temperature, and the amount of thermal NOx generated here is relatively large compared with other locations of the boiler 1. The regeneration rich gas circulation pipe 2 is arranged in the middle part of the boiler 1, so that the nitrogen oxides entering the regeneration rich gas circulation pipe 2 can first enter the middle part of the boiler 1 for suppression, and then diffuse to the top and bottom of the boiler 1 where the temperature is relatively low for suppression, which can greatly improve the thermal NOx suppression effect.

[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 3As shown, the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace 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, Figure 2 and Figure 3 As shown, the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance in the embodiment of the present invention arranges a plurality of 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 plurality of 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] In some embodiments, 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, Figure 2 and Figure 3 As shown, a plurality of regeneration rich gas circulation pipes 2 are divided into two groups, and the two groups of regeneration rich gas circulation pipes 2 are arranged at intervals in the height direction of the furnace body 101, and each group of regeneration rich gas circulation pipes 2 includes eight regeneration rich gas circulation pipes 2, and the eight regeneration rich gas circulation pipes 2 are evenly spaced along the circumference of the furnace body 101, and two regeneration rich gas circulation pipes 2 are arranged on each furnace wall of the furnace body 101. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance of the 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 spaced along the height direction of the furnace body 101, and each group of regeneration rich gas circulation pipes 2 are spaced along the circumference of the furnace body 101, which is conducive to improving the uniformity of the distribution of nitrogen oxides in the first combustion zone 10111, and further conducive to improving the suppression effect of thermal NOx.

[0055] In some embodiments, the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance of the embodiments of the present invention also includes a plurality of primary air ducts 6, and the plurality of primary air ducts 6 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 6 extend into the first combustion zone 10111 of the furnace 1011, and the primary air ducts 6 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 at least some of the primary air ducts 6.

[0056] At least part of the outlet end of the primary air duct 6 extends into the first combustion zone 10111 of the furnace 1011. It can be understood that part of the outlet end of the primary air duct 6 extends into the first combustion zone 10111 of the furnace 1011, or all of the outlet ends of the primary air duct 6 extend into the first combustion zone 10111 of the furnace 1011.

[0057] For example, Figure 4 and Figure 5 As shown, nitrogen oxides enter the first combustion zone 10111 of the furnace 1011 through part of the primary air duct 6. The flue gas low-temperature adsorption regeneration system for nitrogen oxides recycling and furnace balance in the embodiment of the present invention recycles nitrogen oxides to the first combustion zone 10111 of the furnace 1011 through the primary air duct 6, and there is no need to separately set a regeneration rich gas circulation pipe 2 on the furnace body 101 to recycle nitrogen oxides, so that the furnace body 101 of the flue gas low-temperature adsorption regeneration system for nitrogen oxides recycling and furnace balance in the embodiment of the present invention has a simple structure and is easy to manufacture.

[0058] In some embodiments, the flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance of the embodiments of the present invention includes a plurality of secondary air ducts 7, and the plurality of secondary air ducts 7 are 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 7 extend into the first combustion zone 10111 of the furnace 1011, and the secondary air ducts 7 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 at least some of the secondary air ducts 7.

[0059] At least part of the outlet ends of the secondary air ducts 7 extend into the first combustion zone 10111 of the furnace 1011. It can be understood that part of the outlet ends of the secondary air ducts 7 extend into the first combustion zone 10111 of the furnace 1011, or all of the outlet ends of the secondary air ducts 7 extend into the first combustion zone 10111 of the furnace 1011.

[0060] For example, Figure 4 and Figure 5It is shown that nitrogen oxides enter the first combustion zone 10111 of the furnace 1011 through part of the secondary air duct 7. The flue gas low-temperature adsorption regeneration system for nitrogen oxides recycling and furnace balance in the embodiment of the present invention recycles nitrogen oxides to the first combustion zone 10111 of the furnace 1011 through the secondary air duct 7, and it is not necessary to separately set the regeneration rich gas circulation pipe 2 on the furnace body 101 to recycle nitrogen oxides, so that the furnace body 101 of the flue gas low-temperature adsorption regeneration system for nitrogen oxides recycling and furnace balance in the embodiment of the present invention has a simple structure and is easy to manufacture.

[0061] In some embodiments, the adsorption regeneration equipment includes a spray cooling tower 8, an adsorption tower 3 and a regeneration tower 4. The spray cooling tower 8 has a smoke inlet 801 for communicating with the flue 102 and a smoke outlet 802 for discharging the cooled flue gas. The smoke inlet 801 is connected to the flue 102. The adsorption tower 3 has a flue gas inlet 301 and a clean flue gas outlet 302. The flue gas inlet 301 is connected to the smoke outlet 802 of the spray cooling tower 8. The adsorption tower 3 has an adsorbent for adsorbing and purifying the low-temperature flue gas into low-temperature clean flue gas. The regeneration tower 4 is used to heat the adsorbent saturated with adsorption in the adsorption tower 3 to desorb and regenerate it. The regeneration tower 4 has a regeneration rich gas outlet 401 for discharging the regeneration rich gas. The regeneration rich gas outlet 401 is connected to the inlet end of the regeneration rich gas circulation pipe 2.

[0062] For example, Figure 1 and Figure 2 As shown, the flue gas discharged from the flue 102 of the boiler 1 enters the spray cooling tower 8 through the smoke inlet 801, is spray-cooled in the spray cooling tower 8, and then discharged through the smoke outlet 802, so that the temperature of the high-temperature flue gas is reduced to below zero before entering the adsorption tower 3. The nitrogen oxides in the low-temperature flue gas entering the adsorption tower 3 are adsorbed by the adsorbent in the adsorption tower 3, and then become clean flue gas and are discharged through the clean flue gas outlet 302. The adsorbent saturated with adsorption enters the regeneration tower 4 for desorption, and the desorbed adsorbent returns to the adsorption tower 3 for re-adsorption. The regeneration rich gas generated by desorption is discharged through the regeneration rich gas outlet 401, and the discharged nitrogen oxides are heated by the heating device and partially decomposed and enter the regeneration rich gas circulation pipe 2, and enter the furnace 1011 through the outlet end of the regeneration rich gas circulation pipe 2.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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 system for nitrogen oxide recycling and furnace 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 in communication with the furnace; Adsorption regeneration equipment, 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; A chemical reaction device, wherein an alkaline reactant is provided in the chemical reaction device, and the chemical reaction device is respectively connected to the adsorption regeneration device and the inlet end of the regeneration rich gas circulation pipe, and is used for reacting and absorbing part of the nitrogen oxides discharged from the regeneration rich gas outlet; A regeneration rich gas circulation pipe, wherein the inlet end of the regeneration rich gas circulation pipe is connected to the chemical reaction device and the outlet end of the regeneration rich gas circulation pipe extends into the furnace, and is used for partially reacting and absorbing nitrogen oxides discharged from the regeneration rich gas outlet and then transporting them to the furnace.

2. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 1 is characterized in that: The furnace has a first combustion zone, the temperature of the first combustion zone is greater than or equal to 700°C, and the outlet end of the regeneration rich gas circulation pipe extends into the first combustion zone of the furnace for transporting nitrogen oxides to the first combustion zone of the furnace.

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

4. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace 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.

5. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 2 is characterized in that: The outlet end of the regeneration rich gas circulation pipe is arranged adjacent to the edge of the furnace.

6. The flue gas low temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 2 is characterized in that There are multiple regeneration rich gas circulation pipes, and the multiple regeneration rich gas circulation pipes are arranged on the furnace body at intervals.

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

8. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 2 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.

9. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 2 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.

10. The flue gas low-temperature adsorption regeneration system for nitrogen oxide recycling and furnace balance according to claim 1 is characterized in that: The adsorption regeneration equipment comprises: A spray cooling tower, the spray cooling tower having a smoke inlet for communicating with the flue and a smoke outlet for discharging cooled smoke, the smoke inlet being communicated with the flue; 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 spray cooling tower, 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.

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