Urea hydrolysis and pyrolysis denitration ammonia production device
By designing a urea hydrolysis and thermal denitrolysis ammonia production device, a dual-mode ammonia production system is realized, which solves the corrosion and blockage problems in urea hydrolysis technology, and improves the denitrification efficiency and system stability.
Patent Information
- Application Number
- CN202421827716.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-31
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-07-31
AI Technical Summary
The existing urea hydrolysis ammonia production technology has problems in the production of corrosive carbamic acid, equipment damage, pipeline blockage and insufficient compatibility of pyrolysis technology in large power plants, resulting in limited denitrification efficiency and system stability.
A urea hydrolysis and thermal denitrolysis ammonia production device is designed, including a urea solution storage tank, a conveying pump, a hydrolysis machine, a pyrolysis furnace and a flue gas heat exchanger. The dual-mode ammonia production system is realized through three branches, which can be switched to the pyrolysis system when the hydrolysis system fails, ensuring the continuity and stability of the denitrification process.
The system is fault tolerance and continuity, provides operational flexibility, and allows power plants to choose the best ammonia production method according to actual conditions, improving denitrification efficiency and economicality.
Smart Images
Figure CN222855053U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of flue gas denitrification to produce ammonia, in particular to a urea hydrolysis and thermal denitrification to produce ammonia device. Background Art
[0002] In large power plants above 300MW, although urea hydrolysis ammonia production technology is favored due to its low energy consumption, its inherent defects cannot be ignored. The carbamic acid produced during the urea hydrolysis process is highly corrosive, causing damage to the equipment and shortening its service life. At the same time, if the hydrolysis temperature is not properly controlled, the urea solution is prone to crystallization, causing pipeline blockage and affecting the continuous operation of the entire denitrification system. In addition, the existing urea hydrolysis device is not designed to take into account the compatibility with pyrolysis technology, which limits the possibility of technology upgrading and optimization. When faced with corrosion and blockage problems, it is difficult for power plants to flexibly adopt more efficient pyrolysis ammonia production technology to replace or supplement, thus missing the opportunity to improve denitrification efficiency and system stability. Utility Model Content
[0003] In order to solve the above-mentioned problem, that is, to solve the problem raised by the above-mentioned background technology, the utility model proposes a urea hydrolysis and pyrolysis denitrification ammonia production device, which includes a urea solution storage tank, one end of the urea solution storage tank is connected to a delivery pump, and the other end of the delivery pump is provided with three branches; branch one: the other end of the hydrolysis solution regulating valve is connected to the hydrolyzer through a pipeline, the hydrolysis ammonia production port of the hydrolyzer is connected to the ammonia-air mixer through the hydrolysis ammonia production regulating valve, and the other end of the ammonia-air mixer is connected to the denitrification system through the dilution air regulating valve; branch two: the other end of the pyrolysis solution regulating valve group is equipped with a spray gun through a pipeline, the head of the spray gun is partially embedded in the cavity of the pyrolysis furnace, the top of the pyrolysis furnace is connected to the flue gas heat exchanger through the hot air regulating valve, and the bottom of the pyrolysis furnace is connected to the denitrification system through the pyrolysis ammonia production regulating valve; branch three: the other end of the pressure regulating reflux valve is connected to the top of the urea solution storage tank through a pipeline.
[0004] The utility model is further configured as follows: a tube bundle heat exchanger is installed inside the hydrolyzer.
[0005] The utility model is further configured as follows: the hot air range after heat exchange by the flue gas heat exchanger is 550-600°C.
[0006] The beneficial technical effect of the utility model is as follows: the utility model has a dual-mode ammonia production system, which can quickly switch to the pyrolysis system when the urea hydrolysis system fails, ensuring that the denitration process is not affected. This design enhances the fault tolerance of the system and ensures the continuity and stability of the denitration work. At the same time, the dual-system configuration provides operational flexibility, allowing the power plant to select the best ammonia production method according to actual conditions, thereby improving efficiency and economy. BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Figure 1 Shown is a schematic diagram of the structure of the utility model.
[0008] Figure numerals: 1. urea solution storage tank, 2. delivery pump, 3. pressure regulating reflux valve, 4. hydrolysis solution regulating valve, 5. hydrolyzer, 6. pyrolysis solution regulating valve group, 7. pyrolysis furnace, 8. hydrolysis ammonia regulating valve, 9. ammonia-air mixer, 10. hot air regulating valve, 11. flue gas heat exchanger, 12. pyrolysis ammonia regulating valve, 13. dilution air regulating valve, 14. denitrification system, 15. spray gun, 16. tube bundle heat exchanger. DETAILED DESCRIPTION
[0009] Please refer to the attached Figure 1 Those skilled in the art should understand 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.
[0010] The utility model proposes a urea hydrolysis and pyrolysis denitrification ammonia production device, comprising a urea solution storage tank 1, urea hydrolysis and pyrolysis, urea solution preparation and storage system common, when the hydrolyzer 5 fails and cannot be used, pyrolysis is used instead. One end of the urea solution storage tank 1 is connected to a delivery pump 2, and the other end of the delivery pump 2 is provided with three branches;
[0011] Branch 1: The other end of the hydrolysis solution regulating valve 4 is connected to the hydrolyzer 5 through a pipeline, a tube bundle heat exchanger 16 is installed inside the hydrolyzer 5, the hydrolysis ammonia production port of the hydrolyzer 5 is connected to the ammonia-air mixer 9 through the hydrolysis ammonia production regulating valve 8, and the other end of the ammonia-air mixer 9 is connected to the denitrification system 14 through the dilution air regulating valve 13.
[0012] Branch 2: A spray gun 15 is installed at the other end of the pyrolysis solution regulating valve group 6 through a pipeline. The pyrolysis solution regulating valve group 6 regulates the concentration and flow of the urea solution. The head of the spray gun 15 is embedded in the cavity of the pyrolysis furnace 7. The top of the pyrolysis furnace 7 is connected to the flue gas heat exchanger 11 through a hot air regulating valve 10. The heat source is the hot air after heat exchange by the flue gas heat exchanger 11. The hot air range after heat exchange by the flue gas heat exchanger 11 is 550-600°C. The air volume of the hot air is regulated by the hot air regulating valve 10. The bottom end of the pyrolysis furnace 7 is connected to the denitration system 14 through the pyrolysis ammonia production regulating valve 12. Ammonia is produced by pyrolysis reaction in the pyrolysis furnace 7 and enters the subsequent denitration system 14 through the pyrolysis ammonia production regulating valve 12 for denitration reaction.
[0013] Branch three: The other end of the pressure regulating reflux valve 3 is connected to the top of the urea solution storage tank 1 through a pipeline. Since the solution pressures required by the delivery hydrolyzer 5 and the pyrolysis furnace 7 are different, a pressure regulating reflux valve 3 is required to be added at the outlet of the delivery pump 2 to adjust the pressure and flow.
[0014] The pressure regulating reflux valve 3, the pyrolysis solution regulating valve group 6, the pyrolysis furnace 7, the hot air regulating valve 10, the flue gas heat exchanger 11 and the pyrolysis ammonia production regulating valve 12 constitute the newly added device for hydrolysis to pyrolysis. It meets the functional requirements of hydrolysis to pyrolysis to produce ammonia. The pressure regulating reflux valve 3 and the pyrolysis solution regulating valve group 6 are key components in the urea hydrolysis and pyrolysis urea solution preparation and storage system, and they jointly ensure the efficient operation of the system in the pyrolysis ammonia production process. The pressure regulating reflux valve 3 is responsible for adjusting the pressure and flow of the urea solution at the outlet of the delivery pump 2 to meet the special needs of the pyrolysis furnace 7. The pyrolysis solution regulating valve group 6 is used to finely adjust the concentration and flow of the urea solution to ensure that it is fully mixed with the hot air of 550-600℃ when it is sprayed into the pyrolysis furnace 7 to achieve an efficient pyrolysis reaction. The coordinated work of these two valves makes the delivery and pyrolysis process of the urea solution more precise and controllable, meeting the requirements of pyrolysis to produce ammonia.
[0015] Working principle:
[0016] Urea hydrolysis:
[0017] The urea solution stored in the urea solution storage tank 1 is transported to the hydrolyzer 5 through the delivery pump 2 and the hydrolysis solution regulating valve 4 for hydrolysis reaction to generate ammonia. The generated ammonia is then regulated by the hydrolysis ammonia regulating valve 8 to control the flow and pressure of the ammonia to ensure that it smoothly enters the main pipe of the furnace area. In the furnace area, ammonia is mixed with air in the ammonia-air mixer 9 and regulated by the dilution air regulating valve 13 to ensure that the concentration of the mixed ammonia is controlled below 5%. The regulated ammonia is sent to the denitrification system 14 to ensure the smooth progress of the entire denitrification reaction.
[0018] Urea Pyrolysis:
[0019] When the hydrolyzer 5 fails and cannot be used, it is switched to pyrolysis. Since the solution pressures required for the hydrolyzer 5 and the pyrolysis furnace 7 are different, it is necessary to add a pressure regulating reflux valve 3 at the outlet of the delivery pump 2 to adjust the pressure and flow rate, and accurately control the concentration and flow rate of the urea solution through the pyrolysis solution regulating valve group 6. The urea solution directly enters the pyrolysis furnace 7 through the spray gun 15, and undergoes pyrolysis reaction with the 550-600℃ hot air provided by the flue gas heat exchanger 11 to generate ammonia. The air volume of the hot air is adjusted by the hot air regulating valve 10, and the ammonia produced by pyrolysis is sent to the denitration system 14 through the pyrolysis ammonia production regulating valve 12 to ensure the smooth progress of the entire denitration reaction.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] 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 hydrolysis and thermal denitrification ammonia production device, comprising a urea solution storage tank (1), characterized in that: One end of the urea solution storage tank (1) is connected to a delivery pump (2), and the other end of the delivery pump (2) is provided with three branches; Branch 1: The other end of the hydrolysis solution regulating valve (4) is connected to the hydrolyzer (5) through a pipeline, the hydrolysis ammonia production port of the hydrolyzer (5) is connected to the ammonia-air mixer (9) through the hydrolysis ammonia production regulating valve (8), and the other end of the ammonia-air mixer (9) is connected to the denitration system (14) through the dilution air regulating valve (13); Branch 2: A spray gun (15) is installed at the other end of the pyrolysis solution regulating valve group (6) through a pipeline, and the head portion of the spray gun (15) is embedded in the cavity of the pyrolysis furnace (7). The top end of the pyrolysis furnace (7) is connected to a flue gas heat exchanger (11) through a hot air regulating valve (10), and the bottom end of the pyrolysis furnace (7) is connected to a denitration system (14) through a pyrolysis ammonia production regulating valve (12); Branch three: The other end of the pressure regulating reflux valve (3) is connected to the top of the urea solution storage tank (1) through a pipeline.
2. The device for producing ammonia by urea hydrolysis and thermal denitrification according to claim 1, characterized in that: A tube bundle heat exchanger (16) is installed inside the hydrolyzer (5).
3. The device for producing ammonia by urea hydrolysis and thermal denitrification according to claim 1, characterized in that: The temperature of the hot air after heat exchange by the flue gas heat exchanger (11) is in the range of 550-600°C.