Ammonia torch zero discharge system and treatment process

Abstract

The invention provides an ammonia torch zero discharge system and a treatment process, the system comprises an ammonia gas conveying header pipe which is communicated with each ammonia gas discharge device, and further comprises an ammonia gas absorption tower, a liquid inlet of which is communicated with a water inlet pipe, and a gas inlet of which is communicated with the ammonia gas conveying header pipe; a spraying assembly for spraying rising ammonia gas is arranged in the tower top of the ammonia gas absorption tower; an inlet of the circulating pump is communicated with the bottom of the ammonia absorption tower through a pipeline, an outlet pipeline is communicated with the middle of the ammonia absorption tower, the pipeline communicated with an outlet of the circulating pump is also communicated with the ammonia distillation device, and a valve is arranged on the output header pipe; and the propylene cooler is arranged on a pipeline connected with the outlet of the circulating pump. The invention further provides a treatment process of the ammonia torch zero discharge system. The low-temperature deep absorption, continuous concentration and recovery upgrading coupling technology is adopted for the ammonia gas discharged by the ammonia torch, the ammonia gas in the ammonia torch gas is absorbed and concentrated before being discharged into the torch to be combusted, the concentrated ammonia gas is sent back to the ammonia distillation device to be treated, and high-quality ammonia water is obtained.

Description

Technical Field

[0001] The invention relates to the technical field of coal chemical industry, in particular to an ammonia flare zero-emission system and a treatment process. Background Art

[0002] The ammonia flare system is used to treat ammonia gas discharged from liquid ammonia spherical tanks in chemical plants, other ammonia gas emission equipment, and ammonia gas discharged from ammonia evaporation devices. Gaseous ammonia burns at the top of the ammonia flare, which has a great impact on the environment. After the application of this technology, not only can ammonia gas be recovered to produce ammonia water, but also the emission outlet of the ammonia flare system can be guaranteed to meet the emission standards, so as to reduce the impact of direct emission of gaseous ammonia on the environment.

[0003] However, through the analysis of the use of ammonia flares in the existing 1.8 million tons / year and 700,000 tons / year plants and the use of ammonia flares in similar industries, it was found that the combustion of ammonia flares has the following problems:

[0004] In extreme weather conditions, the ammonia flare is very easy to go out or difficult to ignite. This is because the ammonia flare has a low ability to resist strong winds. In normal production, when the wind force is greater than level 5, the ammonia flare is easy to go out, and it goes out 1 to 2 times a month. When the wind force exceeds level 17, the ammonia flare can hardly be ignited. However, after the ammonia flare is extinguished, the vent air is directly discharged without combustion, which will cause a serious environmental pollution accident. In addition, when the ammonia device or ammonia tank is overpressured, the vent valve is quickly fully opened or the safety valve is tripped, a large amount of liquid ammonia will enter the ammonia flare system, which will also cause a large amount of ammonia discharge from the ammonia flare system, resulting in insufficient combustion at the flare head. Furthermore, when the original ammonia flare system design does not have an effective anti-flashback device, when the vent air flow fluctuates greatly during normal production, especially during the intermittent discharge of the vent air, it is very easy to cause the flare combustion gas to flash back, causing secondary accidents.

[0005] In summary, the industry tries to solve the above problems by increasing the fuel gas flow, igniting multiple times, making windproof modifications to the flare head, reducing the nitrogen usage of the ammonia flare main pipe, ensuring that the total gas volume entering the flare head is reduced, and continuously replenishing nitrogen from the ammonia flare main pipe to avoid secondary accidents. However, the effect cannot meet the requirements, and the problems caused by the presence of ammonia combustion in the system have not been completely solved. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide an ammonia flare zero emission system, which can use low-temperature deep absorption, continuous concentration and recovery and quality improvement coupling technology for the ammonia gas emitted by the ammonia flare, absorb the ammonia in the ammonia flare gas before the emission flare is burned, and send it back to the ammonia distillation device for treatment after absorption to obtain high-quality ammonia water for use in the desulfurization and denitrification device to replace liquid ammonia. After treatment by this technology, the ammonia flare achieves zero emission of ammonia, and the recovered ammonia water replaces liquid ammonia to reduce the economic operation cost, achieving environmental benefits while reducing the operating cost of the enterprise's ammonia flare.

[0007] In order to solve the above technical problems, the present invention provides a first invention scheme: an ammonia flare zero emission system, comprising an ammonia gas delivery main pipe, the ammonia gas delivery main pipe is connected to each ammonia gas emission device, and is used to collect ammonia gas released by each ammonia gas emission device, and further comprises:

[0008] An ammonia absorption tower, wherein the liquid inlet is connected to the water inlet pipe, the gas inlet is connected to the ammonia delivery main pipe, a spray assembly is provided inside the top of the ammonia absorption tower, the spray assembly sprays the ammonia rising to the top of the ammonia absorption tower, and the spray assembly is connected to the spray liquid delivery pipe;

[0009] A circulation pump, the inlet of which is connected to the bottom of the ammonia absorption tower through a pipeline, and the outlet of which is connected to the middle of the ammonia absorption tower, is used to drive the low-concentration ammonia water to circulate through the circulation pump, so that the ammonia sent to the ammonia absorption tower is fully contacted and absorbed by the water. The pipeline connected to the outlet of the circulation pump is also connected to the ammonia evaporation device through an output main pipe, and a valve is provided on the output main pipe;

[0010] The propylene cooler is arranged on the pipeline connected to the outlet of the circulation pump and is used to reduce the temperature of the low-concentration ammonia water in the ammonia absorption tower through multiple heat exchanges through the propylene cooler.

[0011] Preferably, the spray assembly includes a first spray assembly and a second spray assembly, both of which are used to spray and wash the ammonia gas rising to the top of the tower, the first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler, the second spray assembly is connected to the low-temperature desalted water delivery pipe, and the second spray assembly is arranged above the liquid outlet of the water inlet pipe.

[0012] Preferably, a density meter and a liquid level indicating regulator are provided at the bottom of the ammonia absorption tower, and the valves provided on the output main pipe are electrically controlled valves, and the electrically controlled valves are electrically connected to the liquid level indicating regulator and the density meter.

[0013] Preferably, an exhaust pipe is connected to the top of the ammonia absorption tower, and the exhaust pipe is connected to a nitrogen compression and drying system. The liquid outlet of the nitrogen compression and drying system is connected to an ammonia evaporation device through a pipeline, and the gas outlet of the nitrogen compression and drying system is connected to an ammonia torch through a torch delivery pipe, which is used to deliver the safety protection gas in the pipeline to the torch.

[0014] Preferably, the ammonia delivery main pipe is provided with a first flow meter and a valve A, and the ammonia delivery main pipe is also provided with a first ammonia delivery branch pipe, and the first ammonia delivery branch pipe is connected to the flare delivery pipe;

[0015] A B valve is provided on the first ammonia delivery branch pipe, the A valve is located on the ammonia delivery main pipe between the first ammonia delivery branch pipe and the first flow meter, the first flow meter is connected to the B valve through the second ammonia delivery branch pipe, the A valve is connected to the second ammonia delivery branch pipe through a pipeline, the A valve, the B valve and the first flow meter are all electrically connected to the controller, and the A valve, the B valve and the first flow meter are all electrically connected to the power supply.

[0016] Preferably, the nitrogen gas pipeline connected to the liquid ammonia spherical tank is also connected to the flare delivery pipe.

[0017] Preferably, a second flow meter and a flame arrester are provided on the flare delivery pipe.

[0018] The second invention scheme provided by the present invention is a treatment process of an ammonia flare zero emission system, comprising the following steps:

[0019] When ammonia flow ≤ 3000m 3 / h, the ammonia collected by the ammonia transport main pipe is sent to the ammonia absorption tower, and the water sprayed in the ammonia absorption tower absorbs 95% of the ammonia at low temperature to form an ammonia solution; the remaining 5% of ammonia that is not absorbed by water rises in the ammonia absorption tower, and is secondary absorbed by the low-temperature desalted water solution and low-concentration ammonia water, so that the ammonia at the top of the ammonia absorption tower is reduced to 0ppm. When the density monitored at the bottom of the ammonia absorption tower reaches 0.960 or the liquid level is higher than the set value, the ammonia solution is transported to the ammonia evaporation device to prepare ammonia water; when the temperature in the ammonia absorption tower is too high, the water vapor flowing out of the top of the ammonia absorption tower will be condensed in the nitrogen compression drying system, and the condensed gas is sent to the ammonia evaporation device;

[0020] When the ammonia flow rate sent to the ammonia absorption tower is ≥3000m 3 / h, part of the ammonia in the ammonia delivery main pipe will be delivered to the first ammonia delivery branch pipe, and then delivered to the ammonia torch for combustion through the first ammonia delivery branch pipe and the flare.

[0021] Preferably, the temperature of the low-temperature desalted water is -2°C to 5°C.

[0022] Preferably, the temperature of the water sprayed in the ammonia absorption tower to absorb 95% of the ammonia is -2°C to 5°C.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] 1. The present invention does not need to increase the fuel gas flow rate, ignite multiple times, carry out windproof modification on the torch head, and reduce the nitrogen usage of the ammonia torch main pipe to ensure that the total gas volume entering the torch head is reduced, and also avoids the occurrence of secondary accidents.

[0025] 2. The present invention delivers the liquid ammonia spherical tank treated by the ammonia torch system, the ammonia discharged by each ammonia discharge device, and the ammonia discharged by the ammonia evaporation device into the ammonia absorption tower through the ammonia delivery main pipe, and deep-cold absorbs the ammonia in low-temperature water. Because low-temperature deep-cold water can increase the absorption amount of ammonia, in order to further reduce the probability of ammonia discharge, a spray component is set in the ammonia absorption tower, and the ammonia rising in the ammonia absorption tower and not absorbed by the deep-cold water is further absorbed by spraying through the spray component. Compared with the ammonia torch discharge system, the ammonia torch is burned by the torch (such as Figure 1 As shown in the figure, the present invention feeds ammonia into an ammonia absorption tower to absorb ammonia in a low temperature environment, and continuously feeds low-concentration ammonia water at the bottom of the ammonia absorption tower back to the middle of the ammonia absorption tower through a circulating pump, which is not only conducive to uniform ammonia water concentration in the ammonia absorption tower, but also can increase the probability of low-concentration ammonia water absorbing ammonia. When the concentration reaches the set value, the ammonia water in the tower will be fed into the ammonia evaporation device to achieve the purpose of reuse. Thus, zero emission of ammonia gas from the ammonia flare is achieved.

[0026] 3. In the ammonia torch zero-emission system provided by the present invention, ammonia will not be discharged to the ammonia torch, thus completely solving the problem of ammonia torch blockage. In addition, the ammonia that was originally required to be sent to the ammonia torch for discharge is fully recovered, thereby increasing the production of ammonia water. Furthermore, the toxic and harmful gases of ammonia are integrated and utilized, which not only solves environmental problems, but also increases the service life of the ammonia torch. At the same time, the ammonia that needs to be discharged is cleaned and treated with low cost and high efficiency, so that ammonia is turned into treasure, and the economic benefits are maximized. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A process flow chart of an ammonia flare system provided in the prior art;

[0028] Figure 2 The present invention provides a process flow chart of an ammonia flare zero emission system.

[0029] Description of reference numerals:

[0030] 1. Liquid ammonia spherical tank, 2. Ammonia emission equipment, 3. Ammonia delivery main pipe, 4. Ammonia absorption tower, 5. Low-temperature desalted water spray assembly, 6. Circulation pump, 7. Propylene cooler, 8. Ammonia evaporation device, 9. Nitrogen compression and drying system, 10. Ammonia torch, 11. Density meter, 12. Water spray assembly, 13. First flow meter, 14. First ammonia delivery branch pipe, 15. Flame arrester, 16. Second flow meter. DETAILED DESCRIPTION

[0031] In order to make the above-mentioned purposes, features and advantages of the embodiments of the present application more obvious and understandable, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application. All other embodiments obtained by ordinary technicians in this field without making creative work belong to the scope of protection of this application.

[0032] The inventors found that ammonia flare combustion has the following problems:

[0033] 1. In extreme weather conditions, the ammonia torch is very easy to go out or difficult to ignite, because the ammonia torch has a low ability to resist strong winds; in normal production, when the wind force is greater than level 5, the ammonia torch is easy to go out, and it goes out 1 to 2 times a month. When the wind force exceeds level 17, the ammonia torch can hardly be ignited. However, after the ammonia torch is extinguished, the vented air is directly discharged without combustion, which will cause a serious environmental pollution accident.

[0034] 2. When the ammonia tank of the ammonia plant is over-pressurized, the vent valve is fully opened quickly or the safety valve is tripped, and a large amount of liquid ammonia will enter the ammonia flare system, causing a large amount of ammonia to be discharged from the ammonia flare system, resulting in incomplete combustion at the flare head.

[0035] 3. In the design of the original ammonia flare system, no effective anti-backfire device was set. When the vent air flow rate fluctuated greatly during normal production, especially during the intermittent discharge of the vent air, it was very easy to cause the flare combustion gas to flash back, causing secondary accidents.

[0036] Therefore, in order to solve the above-mentioned problems, the present invention provides an ammonia flare zero emission system and process, which can use low-temperature deep absorption + continuous concentration + recovery and quality improvement coupling technology for the ammonia gas emitted by the ammonia flare, absorb and concentrate the ammonia in the ammonia flare gas before the emission flare is burned, and send it back to the ammonia distillation device for treatment after concentration to obtain high-quality ammonia water for use in the desulfurization and denitrification device to replace liquid ammonia. After being processed by this technology, the ammonia torch achieves zero emission of ammonia, and the recovered ammonia water replaces liquid ammonia to reduce the economic operation cost, achieving environmental benefits while reducing the operating cost of the enterprise's ammonia torch.

[0037] Reference below Figure 2 An ammonia flare zero emission system and process according to an embodiment of the present invention is described.

[0038] refer to Figure 2 , an ammonia flare zero emission system, including an ammonia delivery main pipe 3, the ammonia delivery main pipe 3 is connected to each ammonia emission device, and is used to collect ammonia released by each ammonia emission device, wherein each ammonia emission device includes a liquid ammonia spherical tank 1, other ammonia emission devices 2 and an ammonia evaporation device 8, the liquid ammonia spherical tank 1, other ammonia emission devices 2 and the ammonia evaporation device 8 are all connected to the inlet of the ammonia delivery main pipe 3, and also includes: an ammonia absorption tower 4, a circulation pump 6 and a propylene cooler 7, wherein the liquid inlet of the ammonia absorption tower 4 is connected to the water inlet pipe 5, the gas inlet of the ammonia absorption tower 4 is connected to the ammonia delivery main pipe 3, a spray component is provided inside the top of the ammonia absorption tower 4, the spray component sprays the ammonia rising to the top of the ammonia absorption tower 4, and the spray component is connected to the spray liquid delivery pipe.

[0039] The inlet of the circulation pump 6 is connected to the bottom of the ammonia absorption tower 4 through a pipeline, and the outlet pipeline of the circulation pump 6 is connected to the middle of the ammonia absorption tower 4, which is used to drive the low-concentration ammonia water to circulate through the circulation pump 6, so that the ammonia sent to the ammonia absorption tower 4 is fully contacted and absorbed by the water. The pipeline connected to the outlet of the circulation pump 6 is also connected to the ammonia evaporation device 8 through an output main pipe, and a valve is provided on the output main pipe;

[0040] The propylene cooler 7 is arranged on the pipeline connected to the outlet of the circulation pump 6 , and is used to reduce the temperature of the low-concentration ammonia water in the ammonia absorption tower 4 through multiple heat exchanges through the propylene cooler 7 .

[0041] Specifically, the spray assembly includes a first spray assembly and a second spray assembly 12, both of which are used to spray and wash the ammonia gas rising to the top of the tower, the first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler 7, the second spray assembly 12 is connected to the low-temperature desalted water delivery pipe, and the second spray assembly 12 is arranged above the liquid outlet of the water inlet pipe 5.

[0042] The purpose of such arrangement is to reabsorb as much ammonia gas that is not absorbed by water and rises in the ammonia absorption tower as possible. The second spraying assembly 12 sprays low-temperature desalted water to ensure the quality of ammonia water prepared by the ammonia evaporation device.

[0043] Specifically, a density meter 11 and a liquid level indicator regulator are provided at the bottom of the ammonia absorption tower 4, and the valves provided on the output main pipe are electrically controlled valves, which are electrically connected to the liquid level indicator regulator and the density meter 11. When the density detected at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level is higher than the set value, the ammonia solution is transported to the ammonia distillation device 8 to produce ammonia water.

[0044] Specifically, an exhaust pipe is connected to the top of the ammonia absorption tower 4, and the exhaust pipe is connected to the nitrogen compression and drying system 9. The liquid outlet of the nitrogen compression and drying system 9 is connected to the ammonia evaporation device 8 through a pipeline, and the gas outlet of the nitrogen compression and drying system 9 is connected to the ammonia torch 10 through a torch delivery pipe, which is used to deliver the safety protection gas in the pipeline to the torch.

[0045] Specifically, the ammonia delivery main pipe 3 is further provided with a first flow meter 13 and a valve A, and the ammonia delivery main pipe 3 is further provided with a first ammonia delivery branch pipe 14, and the first ammonia delivery branch pipe 14 is connected to the flare delivery pipe;

[0046] A B valve is provided on the first ammonia delivery branch pipe 14, and the A valve is located on the ammonia delivery main pipe 3 between the first ammonia delivery branch pipe 14 and the first flow meter 13. The first flow meter 13 is connected to the B valve through a second ammonia delivery branch pipe, and the A valve is connected to the second ammonia delivery branch pipe through a pipeline. The A valve, the B valve and the first flow meter 13 are all electrically connected to the controller, and the A valve, the B valve and the first flow meter 13 are all electrically connected to the power supply.

[0047] Specifically, the nitrogen gas pipeline connected to the liquid ammonia spherical tank 1 is also connected to the flare delivery pipe.

[0048] Specifically, the flare delivery pipe is provided with a second flow meter 16 and a flame arrester 15, and the flame arrester 15 is provided to prevent the flare from backfiring.

[0049] A process for an ammonia flare zero emission system comprises the following steps:

[0050] When ammonia flow ≤ 3000m 3 / h, ammonia discharged normally or accidentally by the liquid ammonia spherical tank 1, the ammonia discharge equipment 2 and the ammonia evaporation device 8 is sent to the ammonia absorption tower 4, and 95% of the ammonia is absorbed by the water sprayed in the ammonia absorption tower 4 at low temperature to form an ammonia solution; the remaining 5% of ammonia that is not absorbed by water rises in the ammonia absorption tower 4, and is secondary absorbed by the low-temperature desalted water solution and water, so that the ammonia at the top of the ammonia absorption tower 4 is reduced to 0ppm. When the density monitored at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level is higher than the set value, the ammonia solution is transported to the ammonia evaporation device 8 to prepare ammonia water; when the temperature in the ammonia absorption tower 4 is too high, the water vapor flowing out of the top of the ammonia absorption tower 4 will be condensed in the nitrogen compression drying system 9, and the condensed gas is sent to the ammonia evaporation device 8;

[0051] When the ammonia flow rate sent to the ammonia absorption tower 4 is ≥3000m 3 / h, part of the ammonia in the ammonia delivery main pipe 3 will be delivered to the first ammonia delivery branch pipe 14, and then delivered to the ammonia torch for combustion through the first ammonia delivery branch pipe 14 and the torch.

[0052] Specifically, the temperature of the low-temperature desalted water is -2°C to 5°C.

[0053] Specifically, the temperature of the water sprayed in the ammonia absorption tower 4 to absorb 95% of the ammonia is -2°C to 5°C.

[0054] Working principle:

[0055] like Figure 1 As shown, an ammonia flare system in the prior art, in which a liquid ammonia collecting spherical tank 1, other ammonia emission equipment 2 and an ammonia evaporation device 8 are all connected to an ammonia delivery main pipe 3, and the ammonia in the ammonia delivery main pipe 3 is directly fed into the ammonia flare for combustion.

[0056] In extreme weather conditions, ammonia torches are very easy to extinguish or difficult to ignite, because ammonia torches have low resistance to strong winds. In normal production, when the wind force is greater than level 5, the ammonia torch is easy to extinguish, and it extinguishes 1 to 2 times a month. When the wind force exceeds level 17, the ammonia torch can hardly be ignited. However, after the ammonia torch is extinguished, the vent air is directly discharged without combustion, which will cause a serious environmental pollution accident. In addition, when the ammonia device or ammonia tank is overpressured, the vent valve is quickly fully opened or the safety valve is tripped, a large amount of liquid ammonia will enter the ammonia torch system, which will also cause a large amount of ammonia discharge from the ammonia torch system, resulting in insufficient combustion at the flare head. Furthermore, when the original ammonia flare system design does not have an effective anti-flashback device, when the vent air flow fluctuates greatly during normal production, especially during the intermittent discharge of the vent air, it is very easy to cause the flare combustion gas to flash back, causing secondary accidents.

[0057] Therefore, in order to avoid the above problems and achieve environmental benefits while reducing the operating costs of the ammonia flare of the enterprise, the present invention makes technical improvements to the existing ammonia flare system.

[0058] like Figure 2 As shown, ammonia discharged normally or accidentally by the liquid ammonia spherical tank 1, the ammonia discharge equipment 2 and the ammonia evaporation device 8 is sent to the ammonia absorption tower 4 through the ammonia delivery main pipe 3, and 95% of the ammonia is absorbed by the water sprayed in the ammonia absorption tower 4 at low temperature to form an ammonia solution; the remaining 5% of ammonia that is not absorbed by water rises in the ammonia absorption tower 4, and is secondary absorbed by the low-temperature desalted water solution and water, and the ammonia at the top of the ammonia absorption tower 4 is reduced to 0ppm. When the monitored density at the bottom of the ammonia absorption tower 4 reaches 0.960 or the liquid level is higher than the set value, the control valve is opened, and the ammonia solution is transported to the ammonia evaporation device 8 through the output main pipe to prepare ammonia water; when the temperature in the ammonia absorption tower 4 is too high, the water vapor flowing out of the top of the ammonia absorption tower 4 will be condensed in the nitrogen compression drying system 9, and the condensed gas is sent to the ammonia evaporation device 8.

[0059] When the liquid ammonia spherical tank 1, the ammonia emission equipment 2 and the ammonia evaporation device 8 are not discharged normally, part of the ammonia in the ammonia delivery main pipe 3 will be sent to the first ammonia delivery branch pipe 14, and then transported to the ammonia torch through the first ammonia delivery branch pipe 14 and the torch for combustion.

[0060] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. An ammonia flare zero emission system, comprising an ammonia delivery main pipe (3), wherein the ammonia delivery main pipe (3) is connected to each ammonia emission device and is used to collect ammonia released by each ammonia emission device, characterized in that: Also includes: An ammonia absorption tower (4), wherein the liquid inlet is connected to the water inlet pipe (5), and the gas inlet is connected to the ammonia delivery main pipe (3). A spray assembly is provided inside the top of the ammonia absorption tower (4), and the spray assembly sprays ammonia rising to the top of the ammonia absorption tower (4). The spray assembly is connected to the spray liquid delivery pipe; A circulation pump (6), the inlet of which is connected to the bottom of the ammonia absorption tower (4) through a pipeline, and the outlet pipeline of which is connected to the middle of the ammonia absorption tower (4), is used to drive the low-concentration ammonia water to circulate through the circulation pump (6), so that the ammonia sent to the ammonia absorption tower (4) is fully contacted with the water and absorbed. The pipeline connected to the outlet of the circulation pump (6) is also connected to the ammonia evaporation device (8) through an output main pipe, and a valve is provided on the output main pipe; The propylene cooler (7) is arranged on the pipeline connected to the outlet of the circulation pump (6) and is used to reduce the temperature of the low-concentration ammonia water in the ammonia absorption tower (4) by multiple heat exchanges through the propylene cooler (7).

2. The ammonia flare zero emission system according to claim 1, characterized in that: The spray assembly comprises a first spray assembly and a second spray assembly (12), the first spray assembly and the second spray assembly (12) are both used for spraying and washing ammonia gas rising to the top of the tower, the first spray assembly is connected to the pipeline connected to the outlet of the propylene cooler (7), the second spray assembly (12) is connected to the low-temperature desalted water delivery pipe, and the second spray assembly (12) is arranged above the liquid outlet of the water inlet pipe (5).

3. The ammonia flare zero emission system according to claim 1, characterized in that: The bottom of the ammonia absorption tower (4) is provided with a density meter (11) and a liquid level indicating regulator, and the valves provided on the output main pipe are electrically controlled valves, and the electrically controlled valves are electrically connected to the liquid level indicating regulator and the density meter (11).

4. The ammonia flare zero emission system according to claim 1, characterized in that: The top of the ammonia absorption tower (4) is connected to an exhaust pipe, which is connected to a nitrogen compression and drying system (9). The liquid outlet of the nitrogen compression and drying system (9) is connected to an ammonia evaporation device (8) through a pipeline. The gas outlet of the nitrogen compression and drying system (9) is connected to an ammonia torch (10) through a torch delivery pipe, which is used to deliver the safety protection gas in the pipeline to the torch.

5. The ammonia flare zero emission system according to claim 4, characterized in that: The ammonia gas delivery main pipe (3) is provided with a first flow meter (13) and a valve A. The ammonia gas delivery main pipe (3) is also provided with a first ammonia gas delivery branch pipe (14), and the first ammonia gas delivery branch pipe (14) is connected to the flare delivery pipe; The first ammonia delivery branch pipe (14) is provided with a B valve, the A valve is located on the ammonia delivery main pipe (3) between the first ammonia delivery branch pipe (14) and the first flow meter (13), the first flow meter (13) and the B valve are connected via a second ammonia delivery branch pipe, the A valve is connected to the second ammonia delivery branch pipe via a pipeline, the A valve, the B valve and the first flow meter (13) are all electrically connected to a controller, and the A valve, the B valve and the first flow meter (13) are all electrically connected to a power supply.

6. The ammonia flare zero emission system according to claim 4, characterized in that: The nitrogen gas transmission pipeline connected to the liquid ammonia spherical tank (1) is connected to the flare delivery pipe.

7. The ammonia flare zero emission system according to claim 4, characterized in that: The flare delivery pipe is provided with a second flow meter (16) and a flame arrester (15).

8. The treatment process of an ammonia flare zero emission system according to any one of claims 1 to 7, characterized in that: The steps include: When ammonia flow ≤ 3000m 3 / h, the ammonia collected by the ammonia transport main pipe (3) is sent to the ammonia absorption tower (4), and 95% of the ammonia is absorbed by the water sprayed in the ammonia absorption tower (4) at low temperature to form an ammonia solution; the remaining 5% of the ammonia that is not absorbed by the water rises in the ammonia absorption tower (4), and is secondary absorbed by the low-temperature desalted water solution and low-concentration ammonia water, so that the ammonia at the top of the ammonia absorption tower (4) is reduced to 0ppm. When the density detected at the bottom of the ammonia absorption tower (4) reaches 0.960 or the liquid level is higher than the set value, the ammonia solution is transported to the ammonia evaporation device (8) to produce ammonia water; when the temperature in the ammonia absorption tower (4) is too high, the water vapor flowing out of the top of the ammonia absorption tower (4) will be condensed in the nitrogen compression drying system (9), and the condensed gas is sent to the ammonia evaporation device (8); When the ammonia flow rate sent to the ammonia absorption tower (4) is ≥3000m 3 / h, part of the ammonia in the ammonia delivery main pipe (3) will be delivered to the first ammonia delivery branch pipe (14), and then delivered to the ammonia torch through the first ammonia delivery branch pipe (14) and the torch for combustion.

9. The treatment process of an ammonia flare zero emission system according to claim 8, characterized in that: The temperature of the low-temperature desalted water is -2°C to 5°C.

10. The treatment process of an ammonia flare zero emission system according to claim 8, characterized in that: The temperature of the water sprayed in the ammonia absorption tower (4) after absorbing 95% of the ammonia is -2°C to 5°C.

Images