Flue gas ammonia desulfurization treatment device for boiler working condition change

Abstract

The utility model discloses a flue gas ammonia desulfurization treatment device for boiler working condition change. The flue gas ammonia desulfurization treatment device comprises a desulfurization tower, a liquid inlet system and a chimney, a smoke outlet of the desulfurization tower is communicated with a chimney pipeline; the desulfurization tower comprises a washing area, an absorption area and a lower spraying area; the liquid inlet system comprises a washing liquid circulating pipeline, an absorption liquid circulating pipeline and a process water circulating pipeline; the washing liquid circulating pipeline is communicated with a washing liquid inlet and a washing liquid circulating opening pipeline of the washing area; and the absorption liquid circulating pipeline is communicated with the absorption liquid inlet of the absorption area and a pipeline of the absorption liquid circulating port. The branch pipe is arranged on the main pipe for conveying the ammonia water, and the adjusting valve with the smaller opening degree is arranged on the branch pipe, so that the water outlet amount of the ammonia water can be adjusted according to the condition of the boiler, the boiler flue gas can be effectively desulfurized under various working conditions, and the problem that the content of particulate matters in the discharged flue gas is too large due to too large flow of the ammonia water is avoided.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of boiler production, in particular to a flue gas ammonia desulfurization treatment device for boiler operating condition change. BACKGROUND

[0002] In the existing desulfurization tower operation process, ammonia desulfurization process is adopted, and 15-25% concentration of ammonia water is used to spray and absorb SO2 in the flue gas. The ammonia water is injected into the spray layer of the absorption section, fully contacts and reacts with the flue gas to realize the absorption of sulfide oxides.

[0003] The desulfurization tower is a commonly used device of the power station, mainly used for treating the flue gas generated by the power station. The original design condition of the desulfurization tower serving in the power station is to treat the flue gas generated when the double-boiler operates. In the double-boiler operation condition, the regulation and control range of the existing ammonia water control system of the desulfurization tower can meet the normal production needs.

[0004] Through optimization of the steam operating condition in actual production, the boiler operating mode is changed from double-boiler operation to single-boiler operation, and the total amount of SO2 generated in the flue gas combustion of the boiler is greatly reduced, so that the ammonia water regulating valve for desulfurization can only be manually controlled in the space of 0%-1.5%, and the ammonia water regulating precision is poor. This results in large fluctuation of the pH value of the absorption liquid and large operation difficulty. If ammonia water with too low pH value is used as the absorption liquid, it is easy to cause the absorption liquid to be unable to completely absorb SO2 in the flue gas, and SO2 escape leads to excessive emission of the chimney exhaust.

[0005] The pH value of the used absorption liquid is too high, which increases the ammonia partial pressure of the solution in the absorption section, increases the ammonia escape, and after the escaped ammonia passes through the absorption section, it continuously reacts with the escaped SO2 to form aerosol, which increases the load of the water washing and demisting section. The reaction product escapes to form ammonium sulfate solution droplets, which increases the risk of excessive particulate matter of the chimney exhaust. With the continuous improvement of environmental protection indicators, the existing environmental protection indicators meet the emission requirements of SO2≤100mg / m 3 , and the flue gas emission requirements are further improved. CONTENT OF THE UTILITY MODEL

[0006] The present application provides a flue gas ammonia desulfurization treatment device for boiler operating condition change, which improves the ammonia water regulating control reliability of the desulfurization tower under various boiler load operating conditions, reduces the risk of SO2 exceeding the standard at the outlet of the sulfur tower, and reduces the labor intensity of manual regulation.

[0007] The present application provides a flue gas ammonia desulfurization treatment device for boiler operating condition change, which improves the ammonia water regulating control reliability of the desulfurization tower under various boiler load operating conditions, reduces the risk of SO2 exceeding the standard at the outlet of the sulfur tower, and reduces the labor intensity of manual regulation.

[0008] The smoke exhaust port of the desulfurization tower is in communication with the chimney pipeline;

[0009] The desulfurization tower comprises a washing zone, an absorption zone, and a lower spraying zone.

[0010] The liquid inlet system comprises a washing liquid circulation pipeline, an absorption liquid circulation pipeline, and a process water circulation pipeline.

[0011] The washing liquid circulation pipeline is in communication with the washing liquid inlet of the washing zone and the washing liquid circulation port.

[0012] The absorption liquid circulation pipeline is in communication with the absorption liquid inlet of the absorption zone and the absorption liquid circulation port.

[0013] The process water circulation pipeline is in communication with the process water inlet of the lower spraying zone and the process water circulation port.

[0014] The absorption liquid circulation pipeline comprises an ammonia water storage tank, a stratified control loop, an oxidation circulation tank, and an absorption liquid return pipeline.

[0015] The ammonia water storage tank is in communication with the liquid inlet end of the stratified control loop.

[0016] The liquid outlet of the oxidation circulation tank is in communication with the absorption liquid inlet, and the liquid inlet of the oxidation circulation tank is in communication with the absorption liquid circulation port through the absorption liquid return pipeline.

[0017] The stratified control loop comprises a main pipe, a branch pipe, a main pipe regulating valve, and a branch pipe regulating valve. One end of the main pipe is in communication with the liquid outlet of the ammonia water storage tank, and the other end is in communication with the absorption liquid return pipeline.

[0018] The two ends of the branch pipe are in communication with the two ends of the main pipe, respectively. The main pipe is provided with the main pipe regulating valve, and the branch pipe is provided with the branch pipe regulating valve.

[0019] Preferably, the branch pipe regulating valve is a DN25 valve, and the main pipe regulating valve is a DN40 valve.

[0020] Preferably, the absorption liquid circulation pipeline comprises an ammonia water pump, and the ammonia water pump is arranged on the pipeline in communication between the ammonia water storage tank and the stratified control loop.

[0021] Preferably, the absorption liquid circulation pipeline comprises a pH detector, and the pH detector is arranged on the absorption liquid return pipeline.

[0022] Preferably, the branch pipe comprises a branch pipe first stop valve and a branch pipe second stop valve, and the branch pipe first stop valve and the branch pipe second stop valve are arranged on the branch pipe on the two opposite outer sides of the branch pipe regulating valve.

[0023] Preferably, the main pipe comprises a main pipe first stop valve and a main pipe second stop valve, and the main pipe first stop valve and the main pipe second stop valve are arranged on the main pipe on the two opposite outer sides of the main pipe regulating valve.

[0024] Preferably, the washing liquid circulating pipeline comprises: a washing pump, a washing backflow pump, a washing liquid storage tank; the liquid outlet of the washing liquid storage tank is in communication with the liquid inlet pipeline of the washing liquid, and the washing pump is arranged on the communication pipeline; the liquid inlet is in communication with the liquid outlet pipeline of the washing liquid, and the washing backflow pump is arranged on the communication pipeline.

[0025] Preferably, the absorption liquid circulating pipeline comprises: an absorption pump; the liquid outlet of the oxidation circulating tank is in communication with the liquid inlet pipeline of the absorption liquid; and the liquid inlet of the oxidation circulating tank is in communication with the absorption liquid circulating pipeline, and the absorption pump is arranged on the communication pipeline.

[0026] The application can produce beneficial effects, including:

[0027] 1) The flue gas ammonia desulfurization treatment device for boiler working condition change provided by the application can adjust the ammonia water outlet flow according to the opened boiler condition by arranging a branch pipe on the main pipe of ammonia water delivery and arranging an adjusting valve with smaller opening on the branch pipe, so as to ensure effective desulfurization of boiler flue gas under various working conditions and avoid the problem of excessive particulate matter content in the discharged flue gas caused by excessive ammonia water flow.

[0028] 2) The flue gas ammonia desulfurization treatment device for boiler working condition change provided by the application can reduce the operation frequency of manual adjusting valve opening during the treatment of boiler flue gas after working condition change, and stabilize the SO2 concentration in the flue gas at the outlet of the desulfurization tower at 2mg / Nm 3 ~ 25mg / Nm 3 , thereby avoiding the problem of non-compliance of flue gas emission caused by fluctuation of SO2 concentration in the discharged flue gas.

[0029] 3) The flue gas ammonia desulfurization treatment device for boiler working condition change provided by the application can ensure that the pH fluctuation range of the absorption liquid of the oxidation circulating tank is reduced to ±0.2 under different boiler working conditions, reduce the SO2 fluctuation at the outlet of the desulfurization tower, and reduce the risk of exceeding the environmental protection index of the chimney. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The main view schematic diagram of the flue gas ammonia desulfurization treatment device for boiler working condition change provided in at least one embodiment of the application;

[0031] Figure 2 The partial enlarged structure schematic diagram; Figure 1

[0032] LEGEND:

[0033] ​The desulfurization tower 2, the washing pump 211, the smoke outlet 11, the washing backflow pump 213, the washing liquid storage tank 214, the air inlet interface 12, the process water tank 3, the process water pump 31, the absorption pump 212, the hierarchical control loop 33, the ammonia water pump 331, the main pipe first stop valve 341, the main pipe regulating valve 342, the main pipe second stop valve 343, the main pipe 345, the branch pipe 332, the branch pipe first stop valve 335, the branch pipe regulating valve 333, the branch pipe second stop valve 334, the oxidation circulating tank 4, the pH detector 321, the absorption liquid backflow pipe 322 and the ammonia water storage tank 311. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0036] The technical means not described in detail in the present application and not used to solve the technical problems of the present application are set according to common knowledge in the art, and various common knowledge setting modes can be implemented.

[0037] Referring to Figures 1-2 The present application provides a flue gas ammonia desulfurization treatment device for boiler working condition change, which comprises a desulfurization tower 2, a liquid inlet system and a chimney.

[0038] The desulfurization tower 2 is provided with a washing liquid inlet and a washing liquid circulation port at intervals, an absorption liquid inlet and an absorption liquid circulation port, and a process water inlet and a process water circulation port.

[0039] The top of the desulfurization tower 2 is provided with a smoke outlet 11, and the chimney is connected to the smoke outlet 11 through a pipeline, and the chimney discharges treated water; the middle of the desulfurization tower 2 is provided with an air inlet interface 12, and the air inlet interface 12 is connected to the exhaust port of the boiler through a pipeline.

[0040] The liquid inlet system includes: a washing liquid circulation pipeline, an absorbent liquid circulation pipeline, and a process water circulation pipeline; the washing liquid circulation pipeline is connected to the washing liquid inlet and the washing liquid circulation port; the absorbent liquid circulation pipeline is connected to the absorbent liquid inlet and the absorbent liquid circulation port; and the process water circulation pipeline is connected to the process water inlet and the process water circulation port.

[0041] The absorbent circulation pipeline includes: an ammonia storage tank 311, an ammonia pump 331, a stratified control loop 33, an oxidation circulation tank 4, and an absorbent return pipe 322. The ammonia storage tank 311 is connected to the inlet of the stratified control loop 33 via the ammonia pump 331. The outlet of the stratified control loop 33 is connected to the absorbent return pipe 322. One end of the absorbent return pipe 322 is connected to the absorbent circulation port, and the other end is connected to the inlet of the oxidation circulation tank 4. The stratified control loop 33 includes: a main pipe 345, a branch pipe 332, a main pipe regulating valve 342, and a branch pipe regulating valve 333. One end of the main pipe 345 is connected to the ammonia pump 331, and the other end is connected to the absorbent return pipe 322. Both ends of the branch pipe 332 are connected to both ends of the main pipe 345. The branch pipe regulating valve 333 is a DN25 valve with an inner diameter of 25 mm. The main control valve 342 is a DN40 valve, which has an inner diameter of 40 mm.

[0042] Setting the branch pipe regulating valve 333 and the main pipe regulating valve 342 in this way can effectively prevent fluctuations in the SO2 content of flue gas during the use of the desulfurization tower 2. At the same time, it can avoid frequent manual operation of the regulating valves, which would increase the workload, and can also prevent the emission of particulate matter in the flue gas from exceeding the standard.

[0043] During use, when the boiler is operating under single-furnace conditions and the SO2 content at the furnace outlet is ≤2500mg / m3, open the DN25 branch pipe regulating valve 333 on the branch pipe 332 and close the main pipe regulating valve 342.

[0044] When the limestone desulfurization system inside the furnace malfunctions, the SO2 content at the furnace outlet is ≥2500 mg / m³. 3 When switching to the regulating loop of the DN40 valve of the main regulating valve 342, the pH of the absorbent is controlled.

[0045] When operating under dual-boiler conditions, the total SO2 emission at the furnace outlet of both boilers is less than ≤2500mg / m³. 3 The absorbent solution is still controlled using a DN25 branch pipe regulating valve 333, ≥2500mg / m³. 3 When switching to the main regulating valve 342 of the DN40 valve, the pH of the absorption liquid is controlled.

[0046] In an embodiment, the absorption liquid circulation pipeline comprises a pH detector 321; the pH detector 321 is arranged on the absorption liquid return pipeline 322. The pH detector 321 can be used to monitor the pH value change of the absorption liquid in the oxidation circulation tank 4 in real time, to determine whether the absorption liquid used meets the SO2 absorption requirement and whether excessive fluctuation occurs.

[0047] In an embodiment, the branch pipeline 332 comprises a branch pipeline first stop valve 335 and a branch pipeline second stop valve 334; the branch pipeline first stop valve 335 and the branch pipeline second stop valve 334 are arranged on the pipelines at both ends of the branch pipeline regulating valve 333, so as to facilitate the stop of the ammonia water flow during maintenance.

[0048] In an embodiment, the main pipeline 345 comprises a main pipeline first stop valve 341 and a main pipeline second stop valve 343; the main pipeline first stop valve 341 and the main pipeline second stop valve 343 are arranged on the pipelines at both ends of the main pipeline regulating valve 342, so as to facilitate the stop of the ammonia water flow during maintenance.

[0049] In an embodiment, the lower part of the desulfurization tower 2 is a washing zone; a washing liquid inlet and a washing liquid circulation port are arranged on the side wall of the washing zone at intervals;

[0050] In an embodiment, the washing liquid circulation pipeline comprises a washing pump 211, a washing return pump 213 and a washing liquid storage tank 214; the outlet of the washing liquid storage tank 214 is in communication with the washing liquid inlet pipeline, and the washing pump 211 is arranged on the communication pipeline; the inlet of the washing liquid storage tank 214 is in communication with the washing liquid outlet pipeline, and the washing return pump 213 is arranged on the communication pipeline. The arrangement can supply washing liquid to the spraying system of the washing zone, and the washing liquid after washing can be recycled.

[0051] In an embodiment, the lower part of the desulfurization tower 2, in which the gas inlet 12 is arranged, is an absorption zone; an absorption liquid inlet and an absorption liquid circulation port are arranged on the absorption zone;

[0052] In an embodiment, the absorption liquid circulation pipeline comprises an absorption pump 212; the outlet of the oxidation circulation tank 4 is in communication with the absorption liquid inlet pipeline; the inlet of the oxidation circulation tank 4 is in communication with the absorption liquid circulation port pipeline, and the absorption pump 212 is arranged on the communication pipeline.

[0053] In an embodiment, the lower part of the desulfurization tower 2 is arranged with a lower spraying zone; a process water inlet and a process water circulation port are arranged on the lower spraying zone;

[0054] In a specific embodiment, the process water circulation pipeline comprises: a process water tank 3, a process water pump 31; the liquid outlet of the process water tank 3 is in communication with the process water inlet pipeline, and the process water pump 31 is arranged on the communication pipeline; the liquid inlet of the process water tank 3 and the process water circulation port are in communication with the pipeline, and the process water circulation pump is arranged on the communication pipeline. The circulation of the process water is realized. The circulation pump is arranged according to the existing conventional desulfurization tower 2 matching equipment, which is not repeated here.

[0055] Embodiment

[0056] The materials and instruments used in the following embodiments are obtained from commercial channels unless otherwise specified; the detection methods used are existing methods unless otherwise specified.

[0057] The ammonia water regulation and control system of two desulfurization towers in the power station of Yunnan Yuntian Petrochemical Co., Ltd. is technically reformed and innovated:

[0058] Before the reform: the desulfurization ammonia water control and regulation frequency is high, the regulation valve is basically maintained at 0.5% to 1.5%, the manual regulation frequency is as high as 142 to 186 times per day, the pH value of the absorption liquid (ammonia water) fluctuates by ±0.5, and the SO2 content in the flue gas discharged from the chimney outlet 11 fluctuates greatly (15mg / m 3 ~ 80mg / m 3 ), and the large fluctuation of the SO2 content in the flue gas is prone to environmental protection risks of non-compliant flue gas emission;

[0059] After the reform: by using the above device, the pH fluctuation range of the absorption liquid is reduced from ±0.5 to ±0.2, the valve opening of the branch pipe regulation valve 333 on the branch pipe 332 is basically maintained at 55% to 65%, the main pipe regulation valve 342 is closed, and no manual intervention is required during the desulfurization process. The SO2 concentration in the flue gas at the outlet of the desulfurization tower is stably maintained at 2mg / Nm 3 ~ 25mg / Nm 3 .

[0060] Conclusion: through the implementation of the absorption liquid PH precise control technology project, the ammonia water manual regulation frequency is greatly reduced (the manual regulation frequency is 142 to 186 times per day), the absorption liquid PH automatic control rate of 100% is achieved, the absorption liquid PH fluctuation frequency is effectively reduced, and the reliability of the flue gas desulfurization system operation is improved.

[0061] Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or make equivalent replacement to part of the technical features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the utility model shall be included in the protection scope of the utility model.

Claims

1. A flue gas ammonia process desulfurization treatment device for boiler operating condition changes, characterized by, The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The desulfurization tower (2) includes a washing zone, an absorption zone, and a lower spraying zone. The absorption liquid circulating pipeline includes an ammonia water storage tank (311), a layered control circuit (33), an oxidation circulating tank (4), and an absorption liquid return pipeline (322). The ammonia water storage tank (311) is in communication with the liquid inlet end of the layered control circuit (33). The liquid outlet of the oxidation circulating tank (4) is in communication with the absorption liquid inlet, and the liquid inlet of the oxidation circulating tank (4) is connected to the absorption liquid circulating port through the absorption liquid return pipeline (322). The layered control circuit (33) includes a main pipe (345), a branch pipe (332), a main pipe regulating valve (342), and a branch pipe regulating valve (333). The two ends of the branch pipe (332) are connected to the two ends of the main pipe (345), respectively. The branch pipe regulating valve (333) is a DN25 valve, and the main pipe regulating valve (342) is a DN40 valve.

2. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The absorption liquid circulating pipeline includes an ammonia water pump (331).

3. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The absorption liquid circulating pipeline includes a pH detector (321).

4. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The branch pipe (332) includes a branch pipe first stop valve (335) and a branch pipe second stop valve (334).

5. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The main pipe (345) includes a main pipe first stop valve (341) and a main pipe second stop valve (343).

6. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The washing liquid circulating pipeline includes a washing pump (211), a washing backflow pump (213), and a washing liquid storage tank (214).

7. The flue gas ammonia process desulphurization treatment device for boiler operating condition change according to claim 1, characterized in that, The absorption liquid circulating pipeline includes an absorption pump (212).

8. The flue gas ammonia process desulphurization treatment device for boiler working condition change according to claim 1, characterized in that, The liquid inlet of the oxidation circulating tank (4) is in communication with the absorption liquid circulating port, and the absorption pump (212) is arranged on the communication pipeline. ​ ​

Images