SNCR (selective non-catalytic reduction) denitration deep efficiency-improving system for circulating fluidized bed
By setting up nitrogen oxide measuring unit and synergist in the SNCR denitrification system of the circulating fluidized bed, the problems of low reaction efficiency and inaccurate nitrogen oxide concentration measurement at low temperatures are solved, and efficient and accurate Nitrogen oxide reduction treatment.
Patent Information
- Application Number
- CN202421123119.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-21
- Publication Date
- 2025-01-07
- Estimated Expiration
- 2034-05-21
AI Technical Summary
In circulating fluidized beds, traditional SNCR denitrification technology is difficult to react effectively at lower temperatures, resulting in low ammonia escape and denitrification efficiency, and the inability to accurately measure the nitrogen oxide concentration in each cyclone separator, affecting the accuracy of reducing agent supply .
The nitrogen oxide measurement unit is provided at the output ends of each cyclone separator. By detecting the nitrogen oxide content before the flue gas is mixed, the amount of reducing agent injection is accurately controlled, and a synergist is introduced when necessary to improve the reaction efficiency.
It achieves efficient denitrification at lower temperatures, reduces ammonia escape, and improves the utilization rate and denitrification efficiency of reducing agents.
Smart Images
Figure CN222305370U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a SNCR denitration system, and more specifically, to a SNCR denitration deep efficiency improvement system for a circulating fluidized bed. Background Art
[0002] The selective non-catalytic reduction (SNCR) flue gas denitrification process is a denitrification method that uses a reducing agent to reduce nitrogen oxides in flue gas to harmless nitrogen and water in the absence of a catalyst. This method first sprays an amino-containing reducing agent into a suitable temperature area (830-1000°C) such as the inlet of a cyclone separator or the outlet of a furnace. Under high temperature, the reducing agent quickly decomposes into ammonia (NH3) and reacts with nitrogen oxides (NOX) in the flue gas to generate nitrogen (N2) and water (H2O). This method uses the furnace or tail flue as a reactor, does not require the addition of a reactor and a catalyst, and has a short construction period.
[0003] However, in actual use, the SNCR process also has its disadvantages:
[0004] ① The reaction needs to be within a relatively high temperature range and have sufficient reaction time to be effective. At lower temperatures, NO and ammonia do not react, causing ammonia to escape, which not only pollutes the environment but also affects the efficiency of denitrification.
[0005] ② There are multiple cyclone separators in the circulating fluidized bed, and the concentration of nitrogen oxides in each cyclone separator is different. The traditional point for measuring nitrogen oxides is in the tail flue, which cannot accurately measure the concentration of nitrogen oxides in each cyclone separator and the measurement time lag is long. It is impossible to accurately adjust the supply of reducing agent according to the concentration of nitrogen oxides in each cyclone separator, which increases the consumption of reducing agent and ammonia escape. Utility Model Content
[0006] The purpose of the utility model is to provide a SNCR denitrification deep efficiency improvement system for a circulating fluidized bed with compact structure, accurate measurement and short time lag in view of the above-mentioned deficiencies in the prior art.
[0007] The technical solution of the utility model is implemented as follows: a SNCR denitrification deep efficiency improvement system for a circulating fluidized bed, comprising a plurality of cyclone separators, a reducing agent spray gun is respectively arranged at the input end of each cyclone separator, each reducing agent spray gun is connected to a reducing agent supply unit, a nitrogen oxide measuring unit is respectively arranged at the output end of each cyclone separator, each nitrogen oxide measuring unit is respectively connected to a nitrogen oxide control cabinet circuit; the reducing agent supply unit is connected to the nitrogen oxide control cabinet circuit.
[0008] In the above-mentioned SNCR denitration deep efficiency improvement system for a circulating fluidized bed, the reducing agent supply unit includes a mixer, the mixer is connected to each reducing agent spray gun through a first pipeline, and the mixer is respectively connected to a reducing agent solution storage tank and a dilution water storage tank through a second pipeline;
[0009] A first control valve is arranged on the first pipeline, and a second control valve is arranged on the second pipeline. The first control valve and the second control valve are respectively connected to the nitrogen oxide measurement unit circuit.
[0010] In the above-mentioned SNCR denitrification deep efficiency improvement system for a circulating fluidized bed, the mixer is connected to a synergist storage tank via a third pipeline, a third control valve is arranged on the third pipeline, and the third control valve is connected to the nitrogen oxide control cabinet circuit.
[0011] In the above-mentioned SNCR denitrification deep efficiency improvement system for a circulating fluidized bed, the output ends of the cyclone separators are connected in parallel through a collecting pipe and then connected to the furnace chamber of the circulating fluidized bed.
[0012] After the utility model adopts the above structure, by arranging a nitrogen oxide measuring unit at the output end of each cyclone separator, that is, detecting the output flue gas of each cyclone separator before it is mixed, the content of nitrogen oxides in each cyclone separator can be accurately and quickly obtained, so that the corresponding amount of reducing agent can be quickly and accurately added for denitrification treatment, which can not only ensure the full utilization of the reducing agent, but also ensure the efficiency of denitrification, avoid ammonia escape caused by excessive addition of reducing agent, and achieve deep denitrification. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will be further described in detail below in conjunction with the embodiments in the accompanying drawings, but this does not constitute any limitation to the present invention.
[0014] Figure 1 It is a structural schematic diagram of the utility model.
[0015] In the figure: 1. cyclone separator; 2. reducing agent spray gun; 3. reducing agent supply unit; 4. nitrogen oxide measuring unit; 5. nitrogen oxide control cabinet; 6. mixer; 7. first pipeline; 7a. first control valve; 8. second pipeline; 8a. second control valve; 9. reducing agent solution storage tank; 10. dilution water storage tank; 11. third pipeline; 11a. third control valve; 12. synergist storage tank; 13. collecting pipe. DETAILED DESCRIPTION
[0016] See also Figure 1 As shown, the utility model is a SNCR denitrification deep efficiency improvement system for a circulating fluidized bed, comprising a plurality of cyclone separators 1, and the output ends of the cyclone separators 1 are connected in parallel through a collecting pipe 13 and then conductively connected to the furnace chamber of the circulating fluidized bed.
[0017] A reducing agent spray gun 2 is respectively arranged at the input end of each cyclone separator 1, and each reducing agent spray gun 2 is connected to a reducing agent supply unit 3. A nitrogen oxide measuring unit 4 is respectively arranged at the output end of each cyclone separator 1, and each nitrogen oxide measuring unit 4 is respectively connected to the circuit of the nitrogen oxide control cabinet 5; the reducing agent supply unit 3 is connected to the circuit of the nitrogen oxide control cabinet 5.
[0018] A nitrogen oxide measurement unit is set at the output end of each cyclone separator, that is, the output flue gas of each cyclone separator is tested before it is mixed, so that the nitrogen oxide content in each cyclone separator can be accurately and quickly obtained, so that the corresponding amount of reducing agent can be quickly and accurately added for denitrification treatment.
[0019] Preferably, the reducing agent supply unit 3 includes a mixer 6, the mixer 6 is connected to each reducing agent spray gun 2 through a first pipeline 7, and the mixer 6 is respectively connected to a reducing agent solution storage tank 9 and a dilution water storage tank 10 through a second pipeline 8;
[0020] A first control valve 7 a is provided on the first pipeline 7 , and a second control valve 8 a is provided on the second pipeline 8 . The first control valve 7 a and the second control valve 8 a are respectively connected to the nitrogen oxide measuring unit 4 in an electrical circuit.
[0021] Further preferably, in this embodiment, the mixer 6 is connected to the synergist storage tank 12 via the third pipeline 11 , and a third control valve 11 a is provided on the third pipeline 11 , and the third control valve 11 a is connected to the nitrogen oxide control cabinet 5 in an electrical circuit.
[0022] The synergist in the synergist storage tank can complete the denitration reaction at a lower temperature. When the boiler combustion load is reduced and the flue gas temperature at the inlet of each cyclone separator is lower than the appropriate temperature range (830-1000°C), the third control valve is opened through the nitrogen oxide control cabinet to allow the synergist to enter the mixer for mixing, thereby maintaining the SNCR denitration high efficiency reaction. During operation, the injection amount of each reducing agent spray gun is controlled according to the nitrogen oxide concentration in each cyclone separator detected by the nitrogen oxide measurement unit, so as to accurately control the amount of reducing agent and improve the utilization rate.
[0023] The above embodiments are preferred implementation modes of the present invention and are only used to facilitate the explanation of the present invention. They are not intended to limit the present invention in any form. Any person with ordinary knowledge in the relevant technical field, if they do not depart from the scope of the technical features of the present invention, can make equivalent embodiments by partial changes or modifications to the technical contents disclosed in the present invention, and they still fall within the scope of the technical features of the present invention without departing from the technical features of the present invention.
Claims
1. A SNCR denitrification deep efficiency improvement system for a circulating fluidized bed, comprising a plurality of cyclone separators (1), wherein a reducing agent spray gun (2) is provided at the input end of each cyclone separator (1), and each reducing agent spray gun (2) is connected to a reducing agent supply unit (3), wherein: A nitrogen oxide measuring unit (4) is provided at the output end of each cyclone separator (1), and each nitrogen oxide measuring unit (4) is connected to a circuit of a nitrogen oxide control cabinet (5); and the reducing agent supply unit (3) is connected to a circuit of the nitrogen oxide control cabinet (5).
2. The SNCR denitrification deep efficiency improvement system for a circulating fluidized bed according to claim 1, characterized in that: The reducing agent supply unit (3) comprises a mixer (6), the mixer (6) is connected to each reducing agent spray gun (2) via a first pipeline (7), and the mixer (6) is respectively connected to a reducing agent solution storage tank (9) and a dilution water storage tank (10) via a second pipeline (8); A first control valve (7a) is arranged on the first pipeline (7), and a second control valve (8a) is arranged on the second pipeline (8). The first control valve (7a) and the second control valve (8a) are respectively connected to the circuit of the nitrogen oxide measurement unit (4).
3. The SNCR denitrification deep efficiency improvement system for a circulating fluidized bed according to claim 2, characterized in that: The mixer (6) is connected to a synergist storage tank (12) via a third pipeline (11), a third control valve (11a) is provided on the third pipeline (11), and the third control valve (11a) is connected to the nitrogen oxide control cabinet (5) in an electrical circuit.
4. The SNCR denitrification deep efficiency improvement system for a circulating fluidized bed according to claim 1, characterized in that: The output ends of the cyclone separators (1) are connected in parallel via a collecting pipe (13) and then conductively connected to the furnace chamber of the circulating fluidized bed.