Boiler flue gas denitration system

Abstract

The utility model discloses a boiler flue gas denitration system, a drainage water collecting pit group is arranged between a mixer and a liquid storage tank, the mixer is respectively communicated with an external ammonia water conveying system and the drainage water collecting pit group, and the output end of the mixer is communicated with a boiler system; the output end of the return pipe is communicated with the liquid storage tank, and the input end of the return pipe is communicated with a pipeline between the drainage sump group and the mixer. The water draining and water collecting pit group is used for collecting condensed water, oil and suspended impurities, so that dryness and cleanness of the boiler flue gas denitration system are guaranteed. The organic amine solution between the liquid storage tank and the mixer is recycled through the backflow pipe, flows out of the liquid storage tank, is purified through the drainage water collection pit set and then enters the mixer to be efficiently mixed with ammonia water, and the concentration of the organic amine solution in the liquid storage tank is increased; therefore, even if the reaction temperature is insufficient in the boiler flue gas denitration process, the mixed liquid can still fully react with the boiler tail gas, and the ammonia escape phenomenon is effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of boiler denitrification, and in particular to a boiler flue gas denitrification system. Background Art

[0002] In the field of flue gas denitrification, the two mainstream technical paths are selective non-catalytic reduction technology (SNCR) and selective catalytic reduction technology (SCR), each with its own application scenarios.

[0003] At present, the boiler denitrification systems in most power plants tend to adopt SNCR technology, using ammonia water as a denitrification agent. However, the traditional method of preparing ammonia water (i.e., a simple mixture of ammonia gas and water) has the problem of low design efficiency, which directly affects the overall efficiency of the boiler denitrification reaction. In addition, the concentration of ammonia water is usually limited to a narrow range of 25% to 28%. This limitation is particularly prominent when the boiler is running at low load, because the temperature conditions required for the SNCR reaction are difficult to meet at this time, resulting in the inability of ammonia water to fully react with the boiler flue gas. This phenomenon not only reduces the denitrification effect, but also triggers a series of negative chain reactions, including corrosion, blockage and even damage to equipment such as air preheaters, dust collectors and flues, posing a serious threat to the safe and stable operation of the equipment. Utility Model Content

[0004] The embodiment of the present application provides a boiler flue gas denitrification system, aiming to ensure that the concentration of ammonia water is adjustable while improving the denitrification efficiency of the boiler flue gas.

[0005] To achieve the above objectives, this application provides the following technical solutions:

[0006] A boiler flue gas denitrification system includes a mixer, a drain sump group, a liquid storage tank and a return pipe; the liquid storage tank is used to store an external organic amine solution; the first output end of the liquid storage tank is connected to the input end of the drain sump group; the output end of the drain sump group is respectively connected to the input end of the return pipe and the second input end of the mixer; the output end of the return pipe is connected to the liquid storage tank; the first input end of the mixer is connected to the output end of the external ammonia water delivery system, and its output end is connected to the boiler system.

[0007] Furthermore, the drainage sump group includes a first drainage sump and a second drainage sump;

[0008] The input end of the first hydrophobic sump is connected to the first output end of the liquid storage tank, the output end of the first hydrophobic sump is connected to the input end of the second hydrophobic sump, and the output end of the second hydrophobic sump is respectively connected to the input end of the reflux pipe and the second input end of the mixer.

[0009] Furthermore, a first electromagnetic flowmeter is provided between the mixer and the reflux pipe for measuring the flow rate of the organic amine solution flowing from the liquid storage tank to the mixer.

[0010] Furthermore, a second electromagnetic flowmeter is provided between the first input end of the mixer and the output end of the external ammonia water delivery system.

[0011] Furthermore, it also includes a wastewater pit; the input end of the wastewater pit is connected to the second output end of the liquid storage tank.

[0012] Furthermore, a one-way valve is provided between the return pipe and the first electromagnetic flowmeter.

[0013] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects:

[0014] In this application, the liquid storage tank is used to store the organic amine solution prepared by an external organic amine preparation system. The hydrophobic sump group is arranged between the mixer and the liquid storage tank to collect condensed water or other forms of water to prevent it from accumulating inside the system to ensure the dryness and cleanliness of the boiler flue gas denitrification system. The reflux pipe is set to return the organic amine solution flowing from the liquid storage tank to the mixer through the hydrophobic sump to the liquid storage tank. The mixer is set to mix the ammonia supplied from the external ammonia supply system and the organic amine solution from the inside of the liquid storage tank to increase the concentration of the organic amine solution in the liquid storage tank, and then increase the nitrogen content in the mixed liquid after the organic amine solution and the ammonia solution are mixed, thereby ensuring that even if the reaction temperature is not enough when the boiler flue gas is denitrified, it can react well with the exhaust gas in the boiler to reduce ammonia escape. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 A schematic diagram of the structure provided in an embodiment of the present application.

[0017] Icons: 10-mixer; 20-liquid storage tank; 30-reflux pipe; 40-first drain sump; 41-second drain sump; 50-first electromagnetic flowmeter; 60-second electromagnetic flowmeter; 70-check valve; 80-wastewater pit; A-external organic amine preparation system; B-external ammonia water delivery system; C-boiler system. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0020] Combine Figure 1 As shown, a boiler flue gas denitrification system includes a mixer 10, a drain sump group, a liquid storage tank 20 and a return pipe 30; the liquid storage tank 20 is used to store an external organic amine solution; the first output end of the liquid storage tank 20 is connected to the input end of the drain sump group; the output end of the drain sump group is respectively connected to the input end of the return pipe 30 and the second input end of the mixer 10; the output end of the return pipe 30 is connected to the liquid storage tank 20; the first input end of the mixer 10 is connected to the output end of the external ammonia water delivery system B, and its output end is connected to the boiler system C.

[0021] The boiler denitrification system involved in this application is composed of key components such as a mixer 10, a hydrophobic sump group, a liquid storage tank 20 and a reflux pipe 30. Among them, the liquid storage tank 20 stores the organic amine solution carefully prepared by the external organic amine preparation system A. The hydrophobic sump group is arranged between the mixer 10 and the liquid storage tank 20. Its main function is to collect and treat condensate or other forms of water, effectively preventing it from accumulating inside the system, thereby ensuring the continuous drying and cleaning of the boiler flue gas denitrification system. The mixer 10 can efficiently mix the ammonia water from the external ammonia water supply system with the organic amine solution treated by the hydrophobic sump group in a specific ratio (preferably 1:1). The mixed liquid is then introduced into the boiler furnace and its tail at 650-1000°C, and reacts chemically with the nitrogen compounds in the flue gas, and is eventually converted into harmless nitrogen and water. The provision of the reflux pipe 30 enables the reflux circulation of part of the organic amine solution that flows out of the liquid storage tank 20 and undergoes hydrophobic water collection treatment, which not only increases the concentration of the organic amine solution in the liquid storage tank 20, but also further enhances the nitrogen content in the mixed liquid, ensuring that even if the reaction temperature is not ideal during the boiler flue gas denitrification process, the mixed liquid can fully react with the boiler exhaust gas, thereby significantly reducing the ammonia escape phenomenon and improving the overall denitrification efficiency and environmental benefits.

[0022] The drain sump group includes a first drain sump 40 and a second drain sump 41. The input end of the first drain sump 40 is connected to the first output end of the liquid storage tank 20, the output end of the first drain sump 40 is connected to the input end of the second drain sump 41, and the output end of the second drain sump 41 is respectively connected to the input end of the return pipe 30 and the second input end of the mixer 10.

[0023] In the above scheme, the hydrophobic sump group is composed of a first hydrophobic sump 40 and a second hydrophobic sump 41. Among them, the first hydrophobic sump 40 is mainly responsible for the task of initial hydrophobic collection, and it can effectively recover substances such as heat and / or water carried in the organic amine solution. Subsequently, the organic amine solution that has passed the initial hydrophobic collection will flow to the second hydrophobic sump 41 for more in-depth secondary treatment. It is feasible that the hydrophobic collection capacities of the first hydrophobic sump 40 and the second hydrophobic sump 41 in this application are arranged in a step-by-step manner. This process aims to further increase the nitrogen content in the organic amine solution to optimize its performance in the subsequent denitrification reaction.

[0024] A first electromagnetic flowmeter 50 is installed between the mixer 10 and the return pipe 30 to measure the flow rate of the organic amine solution from the liquid storage tank 20 to the mixer 10. In the above solution, personnel can use an external control system electrically connected to the first electromagnetic flowmeter 50 to monitor the real-time flow rate of the organic amine solution as it flows into the mixer 10. This ensures the real-time ratio of the organic amine to aqueous ammonia, thereby ensuring the stability of the boiler's out-of-stock status.

[0025] To monitor the real-time flow rate of ammonia supplied to mixer 10 by external ammonia delivery system B, a second electromagnetic flowmeter 60 is installed between the first input of mixer 10 and the output of external ammonia delivery system B to ensure a stable ratio of aqueous ammonia solution to organic amine solution. Alternatively, an ammonia valve can be installed between mixer 10 and external ammonia delivery system B. This valve is electrically connected to second electromagnetic flowmeter 60, thereby enabling real-time control of the start and stop of ammonia supply between mixer 10 and external ammonia delivery system B.

[0026] The boiler flue gas denitrification system of the present application further includes a wastewater pit 80; the input end of the wastewater pit 80 is connected to the second output end of the liquid storage tank 20. The wastewater pit 80 is provided to facilitate the collection and removal of wastewater containing organic amines and / or their byproducts, thereby reducing pollution to the working environment or equipment.

[0027] To facilitate real-time monitoring of the organic amine solution flowing from reflux pipe 30 into liquid storage tank 20, a one-way valve 70 is installed between reflux pipe 30 and first electromagnetic flowmeter 50. This arrangement allows the valve 70 to be opened based on the target organic amine concentration, allowing the high-concentration organic amine solution collected by the drainage sump to be refilled into liquid storage tank 20, reducing resource waste while improving the boiler's denitrification reaction efficiency.

[0028] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0029] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A boiler flue gas denitrification system, characterized in that: It includes a mixer (10), a drainage sump group, a liquid storage tank (20) and a return pipe (30); The liquid storage tank (20) is used to store the external organic amine solution; The first output end of the liquid storage tank (20) is connected to the input end of the drainage sump group; The output end of the drainage sump group is respectively connected to the input end of the return pipe (30) and the second input end of the mixer (10); The output end of the reflux pipe (30) is connected to the liquid storage tank (20); The first input end of the mixer (10) is connected to the output end of the external ammonia water delivery system (B), and the output end thereof is connected to the boiler system (C).

2. The boiler flue gas denitrification system according to claim 1, characterized in that: The drainage sump group includes a first drainage sump (40) and a second drainage sump (41); The input end of the first hydrophobic sump (40) is connected to the first output end of the liquid storage tank (20), the output end of the first hydrophobic sump (40) is connected to the input end of the second hydrophobic sump (41), and the output end of the second hydrophobic sump (41) is respectively connected to the input end of the reflux pipe (30) and the second input end of the mixer (10).

3. The boiler flue gas denitrification system according to claim 1, characterized in that: A first electromagnetic flowmeter (50) is provided between the mixer (10) and the reflux pipe (30), and the first electromagnetic flowmeter (50) is used to measure the flow rate of the organic amine solution flowing from the liquid storage tank (20) to the mixer (10).

4. The boiler flue gas denitrification system according to claim 1, characterized in that: A second electromagnetic flowmeter (60) is provided at the first input end of the mixer (10) and the output end of the external ammonia water delivery system (B).

5. The boiler flue gas denitrification system according to claim 1, characterized in that: It also includes a wastewater pit (80); the input end of the wastewater pit (80) is connected to the second output end of the liquid storage tank (20).

6. The boiler flue gas denitrification system according to claim 3, characterized in that: A one-way valve (70) is provided between the reflux pipe (30) and the first electromagnetic flowmeter (50), and the one-way valve (70) is used to start and stop the reflux of the organic amine solution from the reflux pipe (30) to the liquid storage tank (20).

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