Precise ammonia preparation and spraying device for urea hydrolysis denitration
By using a chain system of adjustment control device and NOx analyzer in the urea hydrolysis and denitrification precision ammonia injection device, combined with the precise zone adjustment control of the ammonia injection grid, the problem of difficult ammonia consumption and ammonia escape in traditional systems is solved, and the optimization and precise control of ammonia production and supply total ammonia injection is achieved and the ammonia escape amount is reduced.
Patent Information
- Application Number
- CN202421146813.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-24
- Publication Date
- 2025-06-03
- Estimated Expiration
- 2034-05-24
AI Technical Summary
Traditional precision ammonia injection systems lack the total regulation control of the total ammonia injection volume and the total ammonia injection volume change with the NOx of the flue gas inlet and outlet, which makes it difficult to effectively adjust the total ammonia consumption and ammonia escape volume.
A precise ammonia ammonia injection device for urea hydrolysis and denitrification is designed, which uses steam control valve, urea solution control valve and dilution air conditioning valve for adjustment and control, and is connected with the NOx analyzer to adjust the total ammonia production according to the changes in NOx concentration indicators, and combines the precise adjustment and control of the ammonia injection grid. An ammonia injection grid designed with long and short pipes is used.
The optimization and precise control of the total ammonia production and ammonia supply is achieved, which reduces the total ammonia escape amount and ensures the local ammonia injection optimization and full mixing reaction of the ammonia injection system in the denitrification reactor.
Smart Images
Figure CN222930577U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of urea denitrification to produce ammonia, in particular to a precise ammonia production and ammonia injection device for urea hydrolysis denitrification. Background Technique
[0002] Urea hydrolysis produces about 37% ammonia gas and other product gases such as water vapor for denitrification reaction. The ammonia consumption is the main cost of production. Reducing the ammonia injection amount and ammonia escape, and minimizing the impact of ammonia escape on the downstream equipment of denitrification. The traditional precise ammonia injection system mainly uses an ammonia injection grid to precisely control the ammonia injection, achieving precise local ammonia injection. The total ammonia production and supply are mainly regulated and controlled by the main regulating valve in front of the ammonia injection grid. The entire system lacks the overall regulation and control of the total ammonia production and ammonia injection amounts with the change of NOx at the inlet and outlet of the flue gas. Sometimes, even if the local ammonia injection is precise, the total ammonia consumption and ammonia escape amount cannot be effectively regulated and controlled, resulting in the failure to effectively reduce the total ammonia consumption after transformation and the still high ammonia escape amount. Content of the Utility Model
[0003] To solve the above problems, that is, the problems proposed in the above background technique, the utility model provides a precise ammonia production and ammonia injection device for urea hydrolysis denitrification, which includes a hydrolyzer. One side of the hydrolyzer is connected with a steam regulating valve and a urea solution regulating valve. Above the hydrolyzer is connected with an ammonia-air mixer. One side of the ammonia-air mixer is connected with an ammonia injection assembly, and the other side is connected with a NOx analyzer through a dilution air regulating valve. The NOx analyzer is also connected with the steam regulating valve and the urea solution regulating valve; the number of the ammonia injection assemblies is three groups, and each group of the ammonia injection assemblies includes a partition regulating valve and an ammonia injection grid. The NOx analyzer is also connected with the partition regulating valve; each group of the ammonia injection grids is composed of a long pipe and a short pipe.
[0004] The beneficial technical effects of the utility model are as follows: The steam regulating valve, the urea solution regulating valve and the dilution air regulating valve are used for adjustment and control, and are interlocked with the NOx analyzer. According to the change of the NOx concentration index at the inlet and outlet, by adjusting the steam amount and the urea solution amount up and down to adjust the total ammonia production amount up and down, the precise optimization control of the total ammonia production and supply is realized, the total ammonia supply amount is precisely optimized, and the total ammonia escape amount is reduced. The precise adjustment and control of the total ammonia production and supply are adopted, combined with the precise partition adjustment and control of the ammonia injection grid. The ammonia injection grid adopts a combined design of long and short pipes to realize the local ammonia injection optimization and precise ammonia injection and full mixing reaction of the ammonia injection system in the denitrification reactor. Description of the Drawings
[0005] Figure 1 Shows the structural schematic diagram of the utility model.
[0006] Reference Signs: 1. Steam regulating valve, 2. Urea solution regulating valve, 3. Hydrolyzer, 4. NOx analyzer, 5. Dilution air regulating valve, 6. Ammonia-air mixer, 7. Ammonia injection grid, 8. Partition regulating valve. Detailed implementation manners
[0007] The preferred implementation manners of the present utility model will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present utility model and are not intended to limit the protection scope of the present utility model.
[0008] The present utility model provides a precise ammonia-making and ammonia-injecting device for urea hydrolysis denitration, which includes a hydrolyzer 3. One side of the hydrolyzer 3 is connected with a steam regulating valve 1 and a urea solution regulating valve 2. Above the hydrolyzer 3 is connected with an ammonia-air mixer 6. One side of the ammonia-air mixer 6 is connected with an ammonia-injecting assembly, and the other side is connected with a NOx analyzer 4 through a dilution air regulating valve 5. The NOx analyzer 4 is also connected with the steam regulating valve 1 and the urea solution regulating valve 2. The number of the ammonia-injecting assemblies is three. Each ammonia-injecting assembly includes a zoning regulating valve 8 and an ammonia-injecting grid 7. The NOx analyzer 4 is also connected with the zoning regulating valve 8. Each ammonia-injecting grid 7 is composed of long pipes and short pipes.
[0009] The present utility model adopts an implementation manner that combines precise regulation and control of the total ammonia-making and ammonia-supplying amount and precise ammonia injection in zones of the ammonia-injecting grid. The urea solution with a concentration of about 50% from the storage tank in the urea solution storage area enters the hydrolyzer 3 through the urea solution regulating valve 2. The hydrolyzer 3 is horizontally arranged with a liquid level of about 600 - 800 mm. Using saturated steam as the heat source, the steam flow is adjusted through the steam regulating valve 1 and enters the hydrolyzer 3 to heat the urea solution to 145 - 155 °C for hydrolysis to produce ammonia. The ammonia with a concentration of about 37% is transported to the ammonia-air mixer 6 in the furnace area. The dilution air volume is adjusted through the dilution air regulating valve 5 to mix the ammonia to a concentration below 5%. The ammonia production concentration is adjusted according to the interlocked change of the NOx concentration. It enters the ammonia-injecting grid 7 through the zoning regulating valve 8 and is sprayed into the denitration reactor for denitration reaction. The total ammonia production amount, concentration of the product gas ammonia and the NOx analyzers 4 at the inlet and outlet of the flue gas are interlocked. According to the change of the NOx concentration index at the inlet and outlet, the steam regulating valve 1, the urea solution regulating valve 2 and the dilution air regulating valve 5 are adjusted and controlled to realize the optimized and precise control of the ammonia-making and ammonia-supplying total amount, precisely optimize the total ammonia-supplying amount and reduce the total ammonia slip. Then the ammonia-injecting grid 7 is arranged in 3×2 to form 6 zones. The ammonia-injecting grid 7 adopts a combined design of long and short pipes. A number of nozzles on the branch pipes are sprayed into the reaction zone to realize the local ammonia injection optimization and precise ammonia injection and full mixing reaction of the ammonia injection spraying system in the denitration reactor.
[0010] Although the present utility model has been described with reference to the preferred embodiments, various improvements can be made thereto and components thereof can be replaced with equivalents without departing from the scope of the present utility model. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any manner. The present utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
[0011] In the description of the present utility model, the terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., which indicate directions or position relationships, are based on the directions or position relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0012] In addition, it should be noted that in the description of the present utility model, unless otherwise clearly defined and limited, the terms "mounted", "connected", "coupled" 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, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.
[0013] The term "comprising" or any other similar term is intended to cover non-exclusive inclusion, so that a process, article, or apparatus / device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes the elements inherent in these processes, articles, or apparatus / device.
[0014] So far, the technical solutions of the present utility model have been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present utility model is obviously not limited to these specific embodiments. Without departing from the principle of the present utility model, those skilled in the art can make equivalent changes or replacements to the relevant technical features, and the technical solutions after these changes or replacements will fall within the protection scope of the present utility model.
Claims
1. A urea hydrolysis and denitrification precise ammonia production and ammonia spraying device, comprising a hydrolyzer (3), characterized in that: The hydrolyzer (3) is connected to a steam regulating valve (1) and a urea solution regulating valve (2) on one side, and an ammonia-air mixer (6) is connected to the top of the hydrolyzer (3). The ammonia-air mixer (6) is connected to an ammonia spraying assembly on one side, and is connected to a NOx analyzer (4) on the other side via a dilution air regulating valve (5). The NOx analyzer (4) is also connected to the steam regulating valve (1) and the urea solution regulating valve (2). There are three groups of ammonia spraying assemblies, and each group of ammonia spraying assemblies includes a zone regulating valve (8) and an ammonia spraying grid (7). The NOx analyzer (4) is also connected to the zone regulating valve (8). Each group of ammonia spraying grids (7) is composed of a long tube and a short tube.