Ammonia water delivery device for flue gas denitration treatment and flue gas denitration equipment

Abstract

The utility model relates to the field of flue gas purification discloses a kind of ammonia water conveying devices and flue gas denitrification equipment of flue gas denitrification, including the front end conveying block, ammonia water evaporator and rear end conveying block connected in sequence, wherein, ammonia water evaporator includes the inner cylinder and outer cylinder that set together, outer cylinder is connected with heat source inlet pipe and heat source discharge pipe, inner cylinder is wound with ammonia water pipe, inner cylinder still has first ammonia gas inlet and first ammonia gas outlet, the inlet end of ammonia water pipe is connected with the front end conveying block, the outlet end of ammonia water pipe is connected with the first ammonia gas inlet of inner cylinder, the first ammonia gas outlet of inner cylinder is connected with the rear end conveying block, the utility model uses ammonia gas evaporator to replace traditional electric heating evaporation device, greatly reduce the working loss and power consumption of electric heater, and ammonia gas that enters rear end is substantially gaseous, and ammonia gas utilization rate is higher when denitration.

Description

Technical Field

[0001] This utility model relates to the field of flue gas purification, specifically to an ammonia water conveying device and a flue gas denitrification equipment for flue gas denitrification treatment. Background Technology

[0002] Nitrogen oxides (NOx) emitted from flue gas are one of the main sources of air pollution and a major cause of phenomena such as acid rain and photochemical smog, posing varying degrees of harm to human health and the living environment.

[0003] SCR technology, as one of the denitrification technologies, is widely used due to its high denitrification efficiency, mature technology, and reliable operation. Currently, the reducing agents in SCR denitrification technology are mainly liquid ammonia, ammonia water, and urea. Liquid ammonia is economical but has lower safety; urea has a complex process and high operating costs; while ammonia water is convenient to transport and has higher safety, thus becoming the preferred choice for SCR denitrification. In China, current denitrification processes using ammonia water as a reducing agent mainly employ evaporation towers or electrically heated evaporation devices to evaporate ammonia gas. During this process, a large amount of water is also evaporated and ultimately enters the flue gas, resulting in high energy consumption for SCR denitrification. Therefore, developing a low-energy-consumption ammonia water denitrification process is particularly urgent. Utility Model Content

[0004] The purpose of this invention is to overcome the problem of simultaneous evaporation of ammonia and water in existing technologies, and to provide an ammonia water conveying device and a flue gas denitrification equipment for flue gas denitrification treatment. In this ammonia water conveying device, the main component evaporated during the evaporation of ammonia water is ammonia.

[0005] To achieve the above objectives, the first aspect of this utility model provides an ammonia water conveying device for flue gas denitrification treatment, comprising a front-end conveying block, an ammonia water evaporator, and a rear-end conveying block connected in sequence. The ammonia evaporator includes an inner cylinder and an outer cylinder nested together. The outer cylinder is connected to a heat source inlet pipe and a heat source outlet pipe. An ammonia pipe is wound around the inner cylinder. The inner cylinder also has a first ammonia inlet and a first ammonia outlet. The inlet end of the ammonia pipe is connected to the front-end conveying block, the outlet end of the ammonia pipe is connected to the first ammonia inlet of the inner cylinder, and the first ammonia outlet of the inner cylinder is connected to the rear-end conveying block.

[0006] Using the above technical solution, a high-temperature medium, such as water, can be injected into the outer cylinder. The lower-temperature ammonia water enters the ammonia water pipe and exchanges heat with the higher-temperature medium. Most of the liquid ammonia water is evaporated into gaseous ammonia and enters the inner cylinder. The liquid mixed in falls into the inner cylinder under the action of gravity, while the gaseous ammonia enters the rear conveying block through the first ammonia outlet. This device uses an ammonia evaporator to replace the traditional electric heating evaporator, which greatly reduces the working loss and power consumption of the electric heater. It achieves a high medium utilization rate with lower energy consumption, realizing energy saving and consumption reduction. Moreover, the ammonia entering the rear is basically gaseous, and the ammonia utilization rate is high during denitrification.

[0007] Preferably, the inlet end of the ammonia water pipe extends downwards inside the outer cylinder and spirals upwards around the inner cylinder from near the lower part of the inner cylinder. The outlet end of the ammonia water pipe is connected to the first ammonia inlet at the upper part of the inner cylinder. This structure maximizes the travel distance of the ammonia water pipe within the outer cylinder, which helps to increase the interaction time between the ammonia water and the heat exchange medium.

[0008] Preferably, the position of the first ammonia outlet on the inner cylinder is higher than the position of the first ammonia inlet thereon. This structure effectively ensures that liquid substances fall under gravity, allowing only gaseous ammonia to enter the rear conveyor block.

[0009] Preferably, the distance between the lowest ammonia pipe and the bottom of the outer cylinder is ≥250mm. This structure provides a certain gap between the ammonia pipe and the bottom of the outer cylinder, facilitating the installation of measuring instruments, such as thermometers.

[0010] Preferably, a level gauge is installed inside the inner cylinder. This structure facilitates the detection of the liquid level inside the inner cylinder.

[0011] Preferably, the front-end conveying block includes an ammonia storage tank and an ammonia delivery pump, the outlet of the ammonia storage tank is connected to the inlet of the ammonia delivery pump, and the outlet of the ammonia delivery pump is connected to the inlet end of the ammonia pipe.

[0012] Preferably, the rear conveying block includes an ammonia-air mixer and an ammonia injection grid, wherein the ammonia injection grid is disposed inside the denitrification reactor, the first ammonia outlet is connected to the second ammonia inlet of the ammonia-air mixer, the air inlet of the ammonia-air mixer is connected to a blower, and the second ammonia outlet of the ammonia-air mixer is connected to the ammonia injection grid.

[0013] Preferably, the distance from the bottom of the outer cylinder to the connection point of the heat source inlet pipe and the outer cylinder is h1, and the distance from the top of the outer cylinder to the connection point of the heat source outlet pipe and the outer cylinder is h2, where h1 and h2 are both greater than or equal to 100 mm. With this structure, the heat source inlet is close to the bottom of the outer cylinder for easy installation, and the heat source outlet is close to the top of the outer cylinder to prevent the outer cylinder from becoming completely filled. Furthermore, the inflow and outflow of the heat source and the ammonia water create convection, which helps improve the evaporation efficiency of the ammonia water.

[0014] Preferably, the length of the portion of the inner cylinder extending beyond the outer cylinder is greater than or equal to 200 mm.

[0015] A second aspect of this invention provides a flue gas denitrification device, wherein the device includes the ammonia water conveying device described in the first aspect of this invention, and also includes a desulfurization tower. The lower part of the inner cylinder extends out of the outer cylinder and is connected to the desulfurization tower. With this technical solution, a portion of the inner cylinder extends out of the outer cylinder, facilitating the installation of a flange at the bottom of the inner cylinder to draw out the liquid. The drawn-out liquid is connected to the overflow port of the desulfurization tower's bottom, serving as makeup water and reducing water consumption in the desulfurization unit. Furthermore, the small amount of incompletely evaporated ammonia contained in the liquid phase is beneficial to the desulfurization process and pH adjustment within the tower.

[0016] Through the above technical solution, a high-temperature medium, such as water, can be injected into the outer cylinder. Lower-temperature ammonia water enters the ammonia water pipe and exchanges heat with the higher-temperature medium. Most of the liquid ammonia water is evaporated into gaseous ammonia gas, which then enters the inner cylinder. The gaseous ammonia water enters the rear conveying block through the first ammonia gas outlet, while the mixed liquid falls into the inner cylinder under gravity and is introduced into the desulfurization tower. This reduces the water consumption of the desulfurization tower, and the introduced liquid is beneficial to the desulfurization process and pH adjustment within the tower. The device provided by this invention uses an ammonia evaporator instead of a traditional electrically heated evaporator, greatly reducing the working loss and power consumption of the electric heater. It achieves high medium utilization with lower energy consumption, realizing energy saving and consumption reduction. Furthermore, the ammonia gas entering the rear is primarily gaseous, resulting in high ammonia utilization during denitrification. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the device provided by this utility model.

[0018] Explanation of reference numerals in the attached figures 1-Ammonia storage tank; 2-Ammonia transfer pump; 3-Outer cylinder; 4-Inner cylinder; 5-Ammonia pipe; 6-Ammonia-air mixer; 7-Fan; 8-Ammonia injection grid; 9-Denitrification reactor; 10-Desulfurization tower; 11-Level gauge; 12-Heat source discharge pipe; 13-Heat source inlet pipe. Detailed Implementation

[0019] In the description of this application, it should be understood that the terms "upper", "lower", "vertical", "horizontal", "top", "bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0020] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] like Figure 1 As shown, an ammonia water conveying device for flue gas denitrification treatment includes a front-end conveying block, an ammonia water evaporator, and a rear-end conveying block connected in sequence. The ammonia evaporator includes an inner cylinder 4 and an outer cylinder 3 nested together. The outer cylinder 3 is connected to a heat source inlet pipe 13 and a heat source outlet pipe 12. An ammonia water pipe 5 is wound around the inner cylinder 4. The inner cylinder 4 also has a first ammonia gas inlet and a first ammonia gas outlet. The inlet end of the ammonia water pipe 5 is connected to the front-end conveying block, the outlet end of the ammonia water pipe 5 is connected to the first ammonia gas inlet of the inner cylinder 4, and the first ammonia gas outlet of the inner cylinder 4 is connected to the rear-end conveying block.

[0023] In this example, the front-end conveying block includes an ammonia storage tank 1 and an ammonia delivery pump 2. The outlet of the ammonia storage tank 1 is connected to the inlet of the ammonia delivery pump 2, and the outlet of the ammonia delivery pump 2 is connected to the inlet end of the ammonia pipe 5.

[0024] The distance from the bottom of the outer cylinder 3 to the connection point of the heat source inlet pipe 13 and the outer cylinder 3 is h1, and the distance from the top of the outer cylinder 3 to the connection point of the heat source outlet pipe 12 and the outer cylinder 3 is h2, where h1 and h2 are both greater than or equal to 100mm.

[0025] The inlet end of the ammonia water pipe 5 extends from top to bottom inside the outer cylinder 3, and spirals from bottom to top around the inner cylinder 4 starting near the lower part of the inner cylinder 4. The outlet end of the ammonia water pipe 5 is connected to the first ammonia gas inlet at the upper part of the inner cylinder 4. The distance between the lowest layer of the ammonia water pipe 5 and the bottom of the outer cylinder 3 is ≥250mm.

[0026] To better discharge ammonia gas, the position of the first ammonia gas outlet on the inner cylinder 4 is higher than the position of the first ammonia gas inlet above it, with a certain drop between the two, and the drop value must be greater than zero.

[0027] The lower part of the inner cylinder 4 extends out of the outer cylinder 3, and the length of the part of the inner cylinder 4 extending out of the outer cylinder 3 is 200mm. A liquid level gauge 11 is installed on the top of the inner cylinder 4, and a liquid level gauge display is provided on the outer cylinder.

[0028] The rear-end conveying block includes an ammonia-air mixer 6 and an ammonia injection grid 8. The ammonia injection grid 8 is installed inside the denitrification reactor 9. Generally, during denitrification, flue gas enters the denitrification reactor 9 from the flue at the bottom of the reactor. The denitrification reactor 9 includes interconnected vertical and horizontal sections. The ammonia injection grid 8 is installed in the vertical section of the denitrification reactor 9, adjacent to the horizontal section. Figure 1 The vertical section shown is that of the denitrification reactor 9.

[0029] The first ammonia outlet on the inner cylinder 4 is connected to the second ammonia inlet of the ammonia-air mixer 6. The air inlet of the ammonia-air mixer 6 is connected to a fan 7. The second ammonia outlet of the ammonia-air mixer 6 is connected to the ammonia injection grille 8.

[0030] This utility model also provides a flue gas denitrification device, which includes the above-mentioned ammonia water conveying device and a desulfurization tower 10. The lower part of the inner cylinder 4 extends out of the outer cylinder 3 and is connected to the overflow port of the desulfurization tower 10 through a pipe.

[0031] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings; however, the present invention is not limited thereto. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention. For example, the lifting structure can be changed to other mechanical lifting structures, including the combination of various specific technical features in any suitable manner. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately. However, these simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. An ammonia water conveying device for flue gas denitrification treatment, characterized in that, It includes a front-end conveyor block, an ammonia evaporator, and a rear-end conveyor block connected in sequence; The ammonia evaporator includes an inner cylinder and an outer cylinder nested together. The outer cylinder is connected to a heat source inlet pipe and a heat source outlet pipe. An ammonia pipe is wound around the inner cylinder. The inner cylinder also has a first ammonia inlet and a first ammonia outlet. The inlet end of the ammonia pipe is connected to the front-end conveying block, the outlet end of the ammonia pipe is connected to the first ammonia inlet of the inner cylinder, and the first ammonia outlet of the inner cylinder is connected to the rear-end conveying block.

2. The ammonia water conveying device according to claim 1, characterized in that, The inlet end of the ammonia water pipe extends from top to bottom inside the outer cylinder and spirals around the inner cylinder from bottom to top, starting from the lower part near the inner cylinder. The outlet end of the ammonia water pipe is connected to the first ammonia gas inlet at the upper part of the inner cylinder.

3. The ammonia water conveying device according to claim 2, characterized in that, The position of the first ammonia outlet on the inner cylinder is higher than the position of the first ammonia inlet thereon.

4. The ammonia water conveying device according to claim 2 or 3, characterized in that, The distance between the lowest layer of the ammonia water pipe and the bottom of the outer cylinder is ≥250mm.

5. The ammonia water conveying device according to claim 4, characterized in that, A level gauge is installed inside the inner cylinder.

6. The ammonia water conveying device according to any one of claims 1-3, characterized in that, The front-end conveying block includes an ammonia storage tank and an ammonia delivery pump. The outlet of the ammonia storage tank is connected to the inlet of the ammonia delivery pump, and the outlet of the ammonia delivery pump is connected to the inlet end of the ammonia pipe.

7. The ammonia water conveying device according to claim 6, characterized in that, The rear-end conveying block includes an ammonia-air mixer and an ammonia injection grid. The ammonia injection grid is installed inside the denitrification reactor. The first ammonia outlet is connected to the second ammonia inlet of the ammonia-air mixer. The air inlet of the ammonia-air mixer is connected to a fan. The second ammonia outlet of the ammonia-air mixer is connected to the ammonia injection grid.

8. The ammonia water conveying device according to claim 7, characterized in that, The distance from the bottom of the outer cylinder to the connection point of the heat source inlet pipe and the outer cylinder is h1, and the distance from the top of the outer cylinder to the connection point of the heat source outlet pipe and the outer cylinder is h2, where h1 and h2 are both greater than or equal to 100mm.

9. The ammonia water conveying device according to claim 4, characterized in that, The length of the portion of the inner cylinder extending beyond the outer cylinder is greater than or equal to 200 mm.

10. A flue gas denitrification device, characterized in that, The flue gas denitrification equipment includes the ammonia water conveying device as described in any one of claims 1-9, and also includes a desulfurization tower, wherein the lower part of the inner cylinder extends out of the outer cylinder and is connected to the desulfurization tower.

Images