Accurate ammonia preparation and spraying device for urea pyrolysis denitration

Abstract

The utility model discloses a urea pyrolysis denitration accurate ammonia preparation ammonia spraying device, which relates to the technical field of urea denitration ammonia preparation, and comprises a pyrolysis furnace, the left side of the pyrolysis furnace is connected with an atomization spray gun, and the left side of the atomization spray gun is connected with a urea solution adjusting valve and a dilution water adjusting valve. The upper part of the pyrolyzing furnace is sequentially connected with a hot air adjusting valve and a hot air heating device, the lower part of the pyrolyzing furnace is connected with a zoning adjusting valve, the zoning adjusting valve is connected with a zoning ammonia spraying grid, the zoning adjusting valve is also connected with a NOx analyzer, and the NOx analyzer is used for adjusting and controlling the urea solution adjusting valve, the dilution water adjusting valve, the hot air heating device and the hot air adjusting valve. According to the method, ammonia production and total ammonia supply amount optimization accurate control is achieved, then partition ammonia injection grid partition adjustment control is combined, an ammonia injection grid is divided into 6 partitions of 3 * 2, long pipes and short pipes are combined, and local ammonia injection optimization accurate ammonia injection and full mixing reaction of an ammonia injection system in a denitration reactor are achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of urea denitration to produce ammonia, in particular to an ammonia spraying device for precise ammonia production by urea thermal denitration. Background Art

[0002] Urea pyrolysis mainly involves spraying urea solution into the pyrolysis furnace through a fine module atomizing spray gun in the furnace area, and then spraying it into the denitrification reactor through an injection system to spray ammonia grid for denitrification reaction. Ammonia consumption is the main cost of production. In recent years, many power plants have carried out technical transformation of precise ammonia spraying for denitrification. The traditional precise ammonia spraying system mainly controls the ammonia spraying accurately, with the goal of ensuring that the outlet NOx distribution unevenness is ≤10% (relative standard deviation rate), the deviation between the NOx set value and the measured value is ≤±5mg / Nm3, and the local ammonia spraying is accurate. The total amount of ammonia production and supply is mainly controlled by the main regulating valve in front of the ammonia spraying grid. The whole system lacks the total regulation control of the total amount of ammonia production and the total amount of ammonia spraying as the flue gas inlet and outlet NOx changes. Even if the local ammonia spraying is accurate, the ammonia escape is still high, which greatly limits its promotion and application. Utility Model Content

[0003] In order to solve the above problems, that is, to solve the problems raised by the above background technology, the utility model proposes a urea pyrolysis denitrification precise ammonia production and ammonia spraying device, including a pyrolysis furnace, an atomizing spray gun is connected to the left side of the pyrolysis furnace, a urea solution regulating valve and a dilution water regulating valve are connected to the left side of the atomizing spray gun, a hot air regulating valve and a hot air heating device are connected in sequence above the pyrolysis furnace, a partition regulating valve is connected below the pyrolysis furnace, the partition regulating valve is connected to a partition ammonia spraying grid, the partition regulating valve is also connected to a NOx analyzer, the urea solution regulating valve, the dilution water regulating valve, the hot air regulating valve and the hot air heating device are all connected to the NOx analyzer, the number of the partition regulating valves is three, the number of the partition ammonia spraying grids is three groups, each group is designed with long and short tubes, and a number of nozzles are installed on each group of long and short tubes.

[0004] The beneficial technical effects of the utility model are as follows: the NOx analyzer adjusts and controls the urea solution regulating valve, the dilution water regulating valve, the hot air heating device, and the hot air regulating valve according to the changes in the inlet and outlet NOx concentration indicators, realizes the optimization and precise control of the total amount of ammonia production and supply, accurately optimizes the total amount of ammonia supply, and reduces the total amount of ammonia escape. Combined with the partitioned ammonia spraying grid partitioned regulation control, the partitioned ammonia spraying grid is divided into 3×2 and arranged into 6 partitions. The partitioned ammonia spraying grid adopts a long and short pipe combination design, and several nozzles on the pipe are sprayed into the reaction zone, so as to realize the local ammonia spraying system in the denitrification reactor. Precise and fully mixed reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 The utility model is shown in the structural diagram.

[0006] Figure numerals: 1. Urea solution regulating valve, 2. Dilution water regulating valve, 3. Atomizing spray gun, 4. NOx analyzer, 5. Dilution air regulating valve, 6. Ammonia-air mixer, 7. Zone regulating valve, 8. Zone ammonia spraying grid. DETAILED DESCRIPTION

[0007] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0008] The utility model proposes a urea pyrolysis denitrification and precise ammonia production and ammonia spraying device, comprising a pyrolysis furnace 4, an atomizing spray gun 3 is connected to the left side of the pyrolysis furnace 4, a urea solution regulating valve 1 and a dilution water regulating valve 2 are connected to the left side of the atomizing spray gun 3, a hot air regulating valve 6 and a hot air heating device 5 are sequentially connected to the top of the pyrolysis furnace 4, a partition regulating valve 7 is connected to the bottom of the pyrolysis furnace 4, the partition regulating valve 7 is connected to a partition ammonia spraying grid 8, the partition regulating valve 7 is also connected to a NOx analyzer 9, the urea solution regulating valve 1, the dilution water regulating valve 2, the hot air regulating valve 6 and the hot air heating device 5 are all connected to the NOx analyzer 9, the number of the partition regulating valves 7 is three, the number of the partition ammonia spraying grids 8 is three, each group is designed with long and short tubes, and a plurality of nozzles are installed on each group of long and short tubes.

[0009] The utility model adopts a combined control implementation method of precise regulation and control of the total amount of ammonia supply for ammonia production and precise ammonia spraying by partition of ammonia spraying grid. About 50% concentration urea solution from a storage tank in a urea solution storage area is regulated by a urea solution regulating valve 1 and a dilution water regulating valve 2 to adjust the flow rate and concentration range of the urea solution within 5-10%, sprayed into a pyrolysis furnace 4 through an atomizing spray gun 3, mixed with primary hot air heated to 550-600°C by a hot air heating device 5 for pyrolysis reaction, the hot air heating device 5 and the hot air regulating valve 6 are regulated to regulate the total amount of ammonia produced and the ammonia concentration to be below 3-5%, and then enters the partition ammonia spraying grid 8 of the injection system through a partition regulating valve 7, and is sprayed into a denitration reactor for denitration reaction. The total amount and concentration of ammonia produced by the product gas ammonia is linked to the flue gas inlet and outlet NOx analyzer 9. According to the changes in the inlet and outlet NOx concentration indicators, the urea solution regulating valve 1, the dilution water regulating valve 2, the hot air heating device 5, and the hot air regulating valve 6 are adjusted and controlled to achieve the optimization and precise control of the total amount of ammonia production and supply, accurately optimize the total amount of ammonia supply, and reduce the total amount of ammonia escape. Combined with the partitioned ammonia spraying grid 8 partition adjustment control, the partitioned ammonia spraying grid is divided into 3×2 and arranged into 6 partitions. The partitioned ammonia spraying grid adopts a long and short pipe combination design, and several nozzles on the pipe are sprayed into the reaction zone to achieve the local ammonia spraying system in the denitrification reactor. Precise and fully mixed reaction.

[0010] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present invention 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 invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0012] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0013] The term "comprise" or any other similar term is intended to cover a non-exclusive inclusion, such that a process, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, article, or apparatus / device.

[0014] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A urea pyrolysis denitrification and precise ammonia production and injection device, comprising a pyrolysis furnace (4), characterized in that: The pyrolysis furnace (4) is connected to an atomizing spray gun (3) on the left side, and a urea solution regulating valve (1) and a dilution water regulating valve (2) are connected to the atomizing spray gun (3) on the left side. The pyrolysis furnace (4) is connected to a hot air regulating valve (6) and a hot air heating device (5) in sequence above the pyrolysis furnace (4). The pyrolysis furnace (4) is connected to a partition regulating valve (7) below the pyrolysis furnace (4). The partition regulating valve (7) is connected to a partition ammonia spraying grid (8). The partition regulating valve (7) is also connected to a NOx analyzer (9). The urea solution regulating valve (1), the dilution water regulating valve (2), the hot air regulating valve (6) and the hot air heating device (5) are all connected to the NOx analyzer (9). There are three partition regulating valves (7) and three groups of partition ammonia spraying grids (8). Each group is designed with long and short tubes, and a plurality of nozzles are installed on each group of long and short tubes.

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