Boiler denitration ammonia water circulating dilution pipeline

Abstract

The utility model belongs to the technical field of flue gas emission and denitration, and relates to a boiler denitration ammonia water circulating dilution pipeline which comprises an ammonia water tank, a dilution pipeline is arranged on the ammonia water tank, a static mixer is arranged on the dilution pipeline, the dilution pipeline is connected to an evaporator, and a demineralized water pipeline and an ammonia water pipeline are connected to the static mixer. The bottom of the ammonia water tank is connected with an SCR pipeline, an SCR pump is arranged on the SCR pipeline, the SCR pipeline is connected to a dilution pipeline, the bottom of the ammonia water tank is connected with an SNCR pipeline, an SNCR pump is arranged on the SNCR pipeline, the SNCR pipeline is connected to the dilution pipeline, a leading-out pipeline is connected to the SNCR pipeline, and an ammonia water spray gun is arranged at the tail end of the leading-out pipeline. The ammonia water concentration is accurately controlled, a denitration system is convenient to adjust, the boiler denitration effect is stabilized, the environment-friendly index is qualified, stable emission is achieved, the ammonia water with the reasonable concentration is used for the denitration technology, qualified emission of boiler flue gas nitric oxide is stabilized, and meanwhile ammonia escape is controlled to be qualified.

Description

Technical Field

[0001] The utility model belongs to the technical field of flue gas denitration, and particularly relates to a denitration ammonia water circulation dilution pipeline for a boiler. Background Art

[0002] The main denitration processes for boiler flue gas emissions are SNCR (in-furnace ammonia injection) and SCR (out-of-furnace catalyst) denitration, which use ammonia water or urea as reducing agents.

[0003] In the coking industry, since ammonia water is produced in the chemical production workshop, the ammonia water is used as a reducing agent for the denitration process of coal-fired boilers, with a concentration of 15%-20%. During the maintenance period of the chemical production phosphoric acid ammonia section or in case of emergency, the concentration of the purchased ammonia water is also about 20%.

[0004] The concentration of ammonia water used in the boiler denitration process is crucial for the denitration efficiency. The optimal concentration range is generally between 5% and 10%. This concentration range is based on the efficiency of the reaction between ammonia water and nitrogen oxides and the consideration of avoiding ammonia escape. If the concentration of ammonia water produced in the chemical production or purchased is too high, although the reaction rate can be accelerated, the risk of ammonia escape will increase, causing environmental pollution and equipment corrosion. Therefore, the ammonia water must be diluted to a reasonable range, not too low. If the ammonia water concentration is too low, it will lead to a reaction time, resulting in incomplete reaction and unable to achieve the denitration effect.

[0005] The current ammonia water dilution process uses a dilution storage tank, mixing in proportion or using a static mixer to dilute the ammonia water before entering the ammonia water tank. Neither of the two methods can adjust the ammonia water concentration in the ammonia water tank in real time and online according to the required concentration.

[0006] Therefore, a denitration ammonia water circulation dilution pipeline for a boiler is proposed. Summary of the Utility Model

[0007] The purpose of the utility model is to provide a denitration ammonia water circulation dilution pipeline for a boiler, which has the function of denitration ammonia water circulation dilution for a boiler, and solves the problem that the existing technology cannot adjust the ammonia water concentration in the ammonia water tank in real time and online according to the required concentration.

[0008] To achieve the above object, the technical solution adopted by the present utility model is that the present utility model provides a boiler denitration ammonia water circulation dilution pipeline, including an ammonia water tank, a dilution pipeline is arranged on the ammonia water tank, a static mixer is arranged on the dilution pipeline, the dilution pipeline is connected to an evaporator, a desalted water pipeline and an ammonia water pipeline are connected to the static mixer, the bottom of the ammonia water tank is connected to an SCR pipeline, an SCR pump is arranged on the SCR pipeline, the SCR pipeline is connected to the dilution pipeline, the bottom of the ammonia water tank is connected to an SNCR pipeline, an SNCR pump is arranged on the SNCR pipeline, the SNCR pipeline is connected to the dilution pipeline, an extraction pipeline is connected to the SNCR pipeline, and the end of the extraction pipeline is provided with an ammonia water spray gun.

[0009] Preferably, the end of the desalted water pipeline is connected to external water supply.

[0010] Preferably, the end of the ammonia water pipeline is connected to chemical production ammonia water, a ammonia supply pipeline is connected to the ammonia water pipeline, the ammonia supply pipeline is connected to external ammonia supply, and a solenoid valve is arranged on the ammonia supply pipeline.

[0011] Preferably, the number of SCR pipelines is 2, the number of SCR pumps is set to 2 corresponding to the number of SCR pipelines, both of the 2 SCR pipelines are connected to the dilution pipeline, the 2 SCR pipelines are communicated through a connecting pipeline, and a manual valve is arranged on the connecting pipeline.

[0012] Preferably, the number of SNCR pipelines is 2, the number of SNCR pumps is set to 2 corresponding to the number of SNCR pipelines, the ends of the 2 SNCR pipelines are connected to each other and then connected to the dilution pipeline through a connecting pipeline.

[0013] Preferably, a solenoid valve and several manual valves are arranged on the dilution pipeline, and a flowmeter is arranged at the end of the dilution pipeline.

[0014] Preferably, flowmeters, check valves, globe valves, solenoid valves and several manual valves are respectively arranged on the desalted water pipeline and the ammonia water pipeline.

[0015] Preferably, solenoid valves and several manual valves are arranged on the SCR pipeline and the SNCR pipeline, and a check valve is also arranged on the SNCR pipeline.

[0016] Preferably, an external discharge pipeline is arranged on one side of the bottom of the ammonia water tank, and a solenoid valve is arranged on the external discharge pipeline.

[0017] Compared with the prior art, the advantages and positive effects of the present utility model are as follows:

[0018] 1. The ammonia water concentration of the present utility model is accurately controlled, which is convenient for the adjustment of the denitration system, stabilizes the boiler denitration effect, the environmental protection indicators are qualified and stably discharged, and the ammonia water with a reasonable concentration is used for the denitration process. While stably discharging the nitrogen oxides in the boiler flue gas up to standard, the ammonia slip is also controlled to be up to standard;

[0019] 2. This utility model has the function of circulating and diluting ammonia water for boiler denitration, and solves the problem in the prior art that the ammonia water concentration in the ammonia water tank cannot be adjusted online in real time according to the required concentration. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of this utility model, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of this utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of a pipeline for circulating and diluting ammonia water for boiler denitration;

[0022] In the above figures, 1. Ammonia water tank, 2. Dilution pipeline, 3. Static mixer, 4. Evaporator, 5. Demineralized water pipeline, 6. Ammonia water pipeline, 7. External water supply, 8. Chemical plant ammonia water, 9. Ammonia supply pipeline, 10. External ammonia supply, 11. SCR pipeline, 12. SCR pump, 13. Connecting pipeline, 14. SNCR pipeline, 15. SNCR pump, 16. Connecting pipeline, 17. Leading-out pipeline, 18. Ammonia water spray gun, 19. Flowmeter, 20. Manual valve, 21. Check valve, 22. Globe valve, 23. Solenoid valve, 24. External discharge pipeline. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] In order to better understand the above-mentioned objects, features and advantages of this utility model, the following will further describe this utility model in conjunction with the drawings and embodiments. It should be noted that, without conflict, the embodiments of this application and the features in the embodiments can be combined with each other.

[0024] Many specific details are set forth in the following description to facilitate a thorough understanding of this utility model. However, this utility model can also be implemented in other ways different from those described herein. Therefore, this utility model is not limited by the specific embodiments disclosed in the following specification.

[0025] Embodiment 1, as Figure 1 shown, a pipeline for circulating and diluting ammonia water for boiler denitration includes an ammonia water tank 1. The ammonia water tank 1 is used to store ammonia water and serves as the core container for ammonia water supply in the denitration process. By centrally storing ammonia water in the ammonia water tank 1, it is convenient to adjust and monitor the concentration of ammonia water to ensure the stable operation of the denitration system.

[0026] A dilution pipeline 2 is provided on the ammonia water tank 1. The dilution pipeline 2 is used to dilute the ammonia water with a relatively high concentration in the ammonia water tank 1 to ensure that the ammonia water reaches a concentration range suitable for the denitrification reaction. Dilution can avoid the risk of excessive ammonia escape and ensure the efficiency of the denitrification reaction at the same time.

[0027] A static mixer 3 is provided on the dilution pipeline 2. The dilution pipeline 2 is connected to an evaporator 4. The evaporator 4 helps to improve the utilization efficiency of ammonia water. Through evaporation, ammonia water can be converted into gaseous ammonia, and the excess ammonia in the ammonia water can be extracted. A desalted water pipeline 5 and an ammonia water pipeline 6 are connected to the static mixer 3. The desalted water pipeline 5 conveys desalted water into the dilution pipeline 2 for diluting the high-concentration ammonia water and maintaining the purity of the water quality. The ammonia water pipeline 6 transports ammonia water into the dilution pipeline 2 to ensure the smooth flow of ammonia water and control the flow rate during the transportation process to cooperate with the dilution process. The static mixer 3 is used to fully mix ammonia water and desalted water to make the dilution process more uniform and stable. Without external power, it uses fluid dynamics to complete uniform mixing to ensure that the ammonia water concentration is uniform and stable.

[0028] The bottom of the ammonia water tank 1 is connected to an SCR pipeline 11. An SCR pump 12 is provided on the SCR pipeline 11. The ammonia water SCR (off-furnace catalysis) denitrification operation is completed inside the SCR pump 12 to complete the off-furnace denitrification process and improve the denitrification efficiency. The SCR pipeline 11 is connected to the dilution pipeline 2 to send the denitrified ammonia water into the dilution pipeline 2. The bottom of the ammonia water tank 1 is connected to an SNCR pipeline 14. An SNCR pump 15 is provided on the SNCR pipeline 14. The SNCR pipeline 14 transports ammonia water to the SNCR pump 15 to complete the SNCR (in-furnace ammonia injection) denitrification operation to meet the requirements of the in-furnace reaction. The SNCR pipeline 14 is connected to the dilution pipeline 2. An extraction pipeline 17 is connected to the SNCR pipeline 14. The extraction pipeline 17 extracts the ammonia water in the SNCR pipeline 14. The end of the extraction pipeline 17 is provided with an ammonia water spray gun 18 to guide the diluted ammonia water to the ammonia water spray gun 18 for spraying, providing the final transmission path to ensure that the ammonia water can be sprayed into the reaction area as needed.

[0029] The following specifically describes the specific designs of the above key components:

[0030] The end of the desalted water pipeline 5 is connected to an external water supply 7. The external water supply 7 is used to supplement the desalted water required by the system to ensure the stable supply of water source during the dilution process, ensure the continuous and reliable water source, and meet the long-term operation requirements of the system.

[0031] The end of the ammonia water pipeline 6 is connected to the chemical plant ammonia water 8, which is the ammonia water produced by the coking industry itself. Through this pipeline supply, industrial by-products are effectively utilized, costs are reduced, and at the same time, the reliability of the ammonia water source is ensured. A ammonia supply pipeline 9 is connected to the ammonia water pipeline 6. The ammonia supply pipeline 9 ensures external supplementation when the ammonia water is insufficient. The ammonia supply pipeline 9 is connected to the external ammonia supply 10, and the external ammonia supply 10 is the ammonia water source purchased externally and serves as a backup supply to avoid affecting the denitration process due to insufficient self-produced ammonia water. A solenoid valve 23 is provided on the ammonia supply pipeline 9 to control the opening and closing of the ammonia supply pipeline 9.

[0032] The number of the SCR pipelines 11 is 2. The number of SCR pumps 12 is set to 2 corresponding to the number of SCR pipelines 11. Both of the 2 SCR pipelines 11 are connected to the dilution pipeline 2. The 2 SCR pipelines 11 are communicated with each other through a connecting pipeline 13, and a manual valve 20 is provided on the connecting pipeline 13. The SCR pipelines 11 are set to 2 to improve redundancy. Each SCR pipeline 11 is connected to the dilution pipeline 2 to ensure the ammonia water supply during the denitration process. The two SCR pipelines 11 are communicated with each other through the connecting pipeline 13, and a manual valve 20 is provided on this pipeline to facilitate manual switching or maintenance when necessary. The number of SCR pumps 12 corresponds to that of the SCR pipelines 11, and each SCR pipeline 11 is equipped with 1 SCR pump 12 to meet the reaction requirements.

[0033] The number of the SNCR pipelines 14 is 2. The number of SNCR pumps 15 is set to 2 corresponding to the number of SNCR pipelines 14. The ends of the 2 SNCR pipelines 14 are connected to each other and then connected to the dilution pipeline 2 through a connecting pipeline 16. The SNCR pipelines 14 are set to 2 to ensure that when one SNCR pipeline 14 fails, the other can continue to work and ensure the reliability of the system. The ends of the two SNCR pipelines 14 are connected to each other and connected to the dilution pipeline 2 through the connecting pipeline 16 to form a closed loop to ensure the full utilization of ammonia water. Each SNCR pipeline 14 is equipped with 1 SNCR pump 15 to provide the necessary power to ensure the continuous supply of ammonia water during the denitration process.

[0034] A solenoid valve 23 and several manual valves 20 are provided on the dilution pipeline 2, and a flow meter 19 is provided at the end of the dilution pipeline 2. The solenoid valve 23 is convenient for opening and closing adjustment, the manual valve 20 is used for manual intervention when maintaining or adjusting the system, and the flow meter 19 monitors the flow in real time.

[0035] Flow meters 19, check valves 21, globe valves 22, solenoid valves 23 and several manual valves 20 are respectively arranged on the demineralized water pipeline 5 and the ammonia water pipeline 6. The flow meter 19 monitors the flow rates of demineralized water and ammonia water in real time. The check valve 21 prevents the reverse flow of the fluid. The globe valve 22 allows for the quick opening or closing of the fluid, facilitating maintenance and troubleshooting. The solenoid valve 23 is used to automatically control the inflow and outflow of the fluid, improving the degree of automation. The manual valve 20 is convenient for manual intervention and adjustment.

[0036] Solenoid valves 23 and several manual valves 20 are arranged on the SCR pipeline 11 and the SNCR pipeline 14. The solenoid valve 23 can automatically control the inflow of ammonia water. The manual valve 20 is convenient for quickly closing or adjusting the flow rate in case of emergency. A check valve 21 is also arranged on the SNCR pipeline 14. The check valve 21 prevents the backflow of the fluid, ensuring that the ammonia water can only flow in a predetermined direction.

[0037] An external discharge pipeline 24 is arranged on one side of the bottom of the ammonia water tank 1. The external discharge pipeline 24 is used to discharge the excess or unused ammonia water to avoid ammonia water overflow. A solenoid valve 23 is arranged on the external discharge pipeline 24 to control the opening and closing of the external discharge pipeline 24.

[0038] The standard parts used in the present utility model can all be purchased from the market. The special-shaped parts can be customized according to the descriptions in the specification and the drawings. The specific connection methods of each part all adopt conventional means such as bolts, rivets, welding, etc. that are mature in the prior art. The machines, parts and equipment all adopt conventional models in the prior art. Coupled with the circuit connection adopting the conventional connection method in the prior art, details are not described herein. The content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0039] The above description is only a preferred embodiment of the present utility model and does not limit the present utility model in other forms. Any person skilled in the art may use the technical content disclosed above to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, as long as it does not depart from the technical solution content of the present utility model, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present utility model still fall within the protection scope of the technical solution of the present utility model.

Claims

1. A boiler denitration ammonia water circulation dilution pipeline, characterized in that It includes an ammonia water tank, on which a dilution pipeline is provided. A static mixer is arranged on the dilution pipeline, and the dilution pipeline is connected to an evaporator. A demineralized water pipeline and an ammonia water pipeline are connected to the static mixer. The bottom of the ammonia water tank is connected to an SCR pipeline, on which an SCR pump is arranged. The SCR pipeline is connected to the dilution pipeline. The bottom of the ammonia water tank is connected to an SNCR pipeline, on which an SNCR pump is arranged. The SNCR pipeline is connected to the dilution pipeline. An extraction pipeline is connected to the SNCR pipeline, and the end of the extraction pipeline is provided with an ammonia water spray gun.

2. The ammonia water circulation dilution pipeline for boiler denitration according to claim 1, characterized in that, The end of the demineralized water pipeline is connected to external water supply.

3. The ammonia water circulation dilution pipeline for boiler denitration according to claim 1, characterized in that, The end of the ammonia water pipeline is connected to chemical production ammonia water. A ammonia supply pipeline is connected to the ammonia water pipeline, and the ammonia supply pipeline is connected to external ammonia supply. A solenoid valve is arranged on the ammonia supply pipeline.

4. A boiler denitration ammonia water circulation dilution pipeline according to claim 1, characterized in that, The number of the SCR pipelines is 2, and the number of the SCR pumps is set to 2 corresponding to the number of the SCR pipelines. Both of the 2 SCR pipelines are connected to the dilution pipeline, and the 2 SCR pipelines are communicated through a connecting pipeline. A manual valve is arranged on the connecting pipeline.

5. A boiler denitration ammonia water circulation dilution pipeline according to claim 1, characterized in that, The number of the SNCR pipelines is 2, and the number of the SNCR pumps is set to 2 corresponding to the number of the SNCR pipelines. The ends of the 2 SNCR pipelines are connected to each other and then connected to the dilution pipeline through a connecting pipeline.

6. The ammonia water circulation dilution pipeline for boiler denitration according to claim 1, characterized in that, A solenoid valve and several manual valves are arranged on the dilution pipeline, and a flowmeter is arranged at the end of the dilution pipeline.

7. A boiler denitration ammonia water circulation dilution pipeline according to claim 1, characterized in that, A flowmeter, a check valve, a globe valve, a solenoid valve and several manual valves are respectively arranged on the demineralized water pipeline and the ammonia water pipeline.

8. A boiler denitration ammonia water circulation dilution pipeline according to claim 1, characterized in that, A solenoid valve and several manual valves are arranged on the SCR pipeline and the SNCR pipeline, and a check valve is also arranged on the SNCR pipeline.

9. A denitrification ammonia water circulation dilution pipeline for a boiler according to claim 1, characterized in that, An external discharge pipeline is arranged on one side of the bottom of the ammonia water tank. A solenoid valve is arranged on the external discharge pipeline.

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