Efficient oxidation air system suitable for wet-process double-tower desulfurization

Abstract

The utility model discloses an efficient oxidation air system suitable for wet double-tower desulfurization, which comprises a first oxidation fan, a second oxidation fan, a third oxidation fan, a fourth oxidation fan, a primary tower, an oxidation air pipe network, a secondary tower and an oxidation air spray gun, the first oxidation fan, the second oxidation fan, the third oxidation fan and the fourth oxidation fan are all connected to the oxidation air main pipes, the oxidation air main pipes are provided with communication valves, and the number of the oxidation air main pipes is two. Through the unique design that the first-stage tower adopts a pipe network type and the second-stage tower adopts a spray gun type, the air pressure of the first-stage tower and the air pressure of the second-stage tower are matched; therefore, the oxidation fan system of the primary tower and the oxidation fan system of the secondary tower are arranged in a combined mode, the number of the oxidation fans can be reduced, the oxidation air system is optimized, for example, when the oxidation fans of the primary tower and the secondary tower are in two-operation and one-standby modes, 2-3 oxidation fans can be reduced by arranging the oxidation fan system in a combined mode, the system is simpler, and therefore the occupied area and investment of equipment are saved.

Description

Technical Field

[0001] The utility model relates to the technical field of wet double-tower desulfurization, in particular to a high-efficiency oxidation air system suitable for wet double-tower desulfurization. Background Art

[0002] Limestone-gypsum wet desulfurization is a flue gas desulfurization process widely used in coal-fired power plants. It has the advantages of mature technology, high desulfurization efficiency and wide application of coal. For ultra-low emissions of high-sulfur coal-fired units, a double-tower double-circulation limestone-gypsum wet desulfurization process is usually required. Through reasonable combination configuration of two-stage tower circulation pumps and operation efficiency distribution, the system desulfurization efficiency can reach more than 99.65%, and the inlet SO2 concentration can reach 10000mg / m 3 (standard state, dry basis, 6% O2) or above, the outlet SO2 emission concentration can still be no higher than 35mg / m 3 (standard state, dry basis, 6% O2) ultra-low emission requirements.

[0003] During the ultra-low emission transformation of coal-fired power plants, the dual-tower dual-circulation desulfurization system emphasizes high-sulfur coal quality. High-power oxidation fans are usually selected with large design margins, which have better economy under design conditions. However, when the coal quality is lower than the design condition and the load is low, there will be too many oxidation fans in operation and high operating energy consumption. In actual operation, the oxidation air volume entering the absorption tower is much higher than the actual demand. On the one hand, it causes excessive energy consumption of the fan. On the other hand, excessive oxidation air will aggravate the generation of foam in the tower, causing the liquid level in the absorption tower to be artificially high. In severe cases, it may even cause slurry overflow. This problem is more prominent when the unit is running at low load for a long time, and it is not conducive to the flexible operation of the thermal power unit.

[0004] In general, separate oxidation fans are installed in the first and second towers of a double-tower desulfurization device. The common configuration is that three oxidation fans are installed in the first and second towers respectively (two in operation and one in standby). In actual operation, due to the small amount of desulfurization in the second tower, the demand for oxidation air is low. At the same time, the pH value of the slurry in the second tower is high, and the oxidation rate of calcium sulfite is low. The oxidation effect is not good in actual operation. Therefore, it is not economical to configure an oxidation fan for the second tower alone, which leads to a complex system and a large footprint.

[0005] It is more economical to use a shared oxidation air system for the first and second towers. However, in actual operation, due to the different liquid levels in the two absorption towers and the different buried depths of the oxidation air ducts in the two slurry pools, the oxidation air system resistances of the two towers are different. Especially when the liquid level in the second tower is low and the liquid level in the first tower is high, the oxidation air system resistance of the first tower is large, and the oxidation air volume allocated by the first tower will be significantly lower than the design value, resulting in poor oxidation effect of the slurry in the first tower, affecting the quality of gypsum produced by the system. If the oxidation air volume of the first and second towers is simply adjusted by valves, serious energy waste will result.

[0006] There are many ways to disperse the slurry with air. Currently, the commonly used oxidation air systems are mainly pipe network type and spray gun type. The pipe network type produces small bubble particle size, high oxidation efficiency, and a wide adjustable range of installation height, but the structure is complex. In order to avoid clogging of the jet holes, the oxidation fan must be kept running continuously. The spray gun type oxidation air duct has a simple structure and is not easy to clog, but the bubbles blown in are large, the oxidation efficiency is low, and its installation height is restricted by the agitator in the tower, and the adjustable range is very small.

[0007] In summary, for wet double-tower desulfurization, this application aims to propose an efficient oxidation air system suitable for wet double-tower desulfurization to achieve the purpose of safe, economical, efficient and low-consumption operation. Utility Model Content

[0008] The purpose of the utility model is to provide a high-efficiency oxidation air system suitable for wet double-tower desulfurization to solve the problems raised in the above-mentioned background technology.

[0009] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0010] A high-efficiency oxidation air system suitable for wet double-tower desulfurization, comprising a first oxidation air fan, a second oxidation air fan, a third oxidation air fan, a fourth oxidation air fan, a first-level tower, an oxidation air duct network, a second-level tower and an oxidation air spray gun, wherein the first oxidation air fan, the second oxidation air fan, the third oxidation air fan and the fourth oxidation air fan are all connected to an oxidation air main pipe, a connecting valve is installed on the oxidation air main pipe, two oxidation air main pipes are provided, the two oxidation air main pipes are respectively connected to one side of the first-level tower and the second-level tower, the oxidation air main pipe is connected to the oxidation air duct of the first-level tower, the oxidation air duct of the first-level tower is connected to the cooling water main pipe, and the oxidation air duct of the first-level tower is connected to the cooling water main pipe. The oxidation air main pipe on one side of the secondary tower is connected to the oxidation air duct of the secondary tower, and the oxidation air duct of the secondary tower is connected to the oxidation air duct through a second cooling water regulating valve and a second cooling water nozzle. The oxidation air duct of the secondary tower is connected to the oxidation air spray gun in the secondary tower through a number of second oxidation air branch pipes. The oxidation air spray gun is provided with a tower support, and each of the oxidation air spray guns is installed on the agitator.

[0011] Preferably, the first oxidation fan, the second oxidation fan, the third oxidation fan and the fourth oxidation fan are connected to the oxidation air main through a first valve, a second valve, a third valve and a fourth valve respectively.

[0012] Preferably, a first regulating valve and a first flow meter are installed at the connection between the oxidation air main pipe and the first-stage tower oxidation air duct.

[0013] Preferably, a first cooling water regulating valve and a first cooling water nozzle are installed at the connection between the first-stage tower oxidation air duct and the cooling water main pipe.

[0014] Preferably, a second regulating valve and a second flow meter are installed at the connection between the oxidation air main pipe and the secondary tower oxidation air duct.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The present application adopts a unique design of using a pipe network type for the first-level tower and a spray gun type for the second-level tower, so that the wind pressures of the first and second-level towers are matched, thereby merging the oxidation fan systems of the first and second-level towers, which can reduce the number of oxidation fans and optimize the oxidation wind system. For example, when the oxidation fans of the original first and second-level towers are two in operation and one in standby, 2-3 oxidation fans can be reduced by merging the oxidation fan systems, and the system is more concise, thereby saving equipment space and investment; when the wind pressures of the first and second towers are close, the oxidation fan systems of the first and second towers are merged, and the air volume of each is adjusted more sensitively by valves, which can reduce unnecessary pressure head loss. In addition, if the oxidation fans of the original first and second towers are two in operation and one in standby, they can be merged into three in operation and one in standby, which not only reduces the number of oxidation fans, but also increases the gradient of matching the number of operating oxidation fans with the unit load by one level, which is more conducive to adjusting the number of operating fans according to the unit load, thereby Further energy saving and consumption reduction is achieved; when the conventional first and second tower oxidation air systems are operated independently, the air volumes of each are not adjustable. If they are simply combined and operated through a connecting pipe, the adjustment is difficult due to the mismatch of wind pressure. The unique design of using a pipe network type for the first tower and a spray gun type for the second tower makes the wind pressure of the first and second towers match, and it is more sensitive to adjust the air volumes of the first and second towers, thereby achieving flexible control; for the first tower of the double-tower desulfurization system, due to its large oxygen consumption and low spray gun oxidation efficiency, it is more efficient to use a pipe network type; for the second tower, due to its small desulfurization volume and low demand for oxidizing air, the pipe network type is prone to clogging, and the spray gun type is more stable. Through optimized design, the combination of the two is applied to the double-tower desulfurization system, and the entire system is more stable and efficient; the present application achieves the advantages of energy saving and consumption reduction, flexible control, safety, stability and efficiency by optimizing the high-efficiency oxidation air system. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a structural diagram of the double-tower desulfurization oxidation air system of the utility model;

[0018] Figure 2 This is the structural diagram of the oxidation air duct network in the first-stage tower of the utility model;

[0019] Figure 3 This is a structural diagram of the oxidation air spray gun in the two-stage tower of the utility model.

[0020] In the figure:

[0021] 1. The first oxidation fan; 2. The second oxidation fan; 3. The third oxidation fan; 4. The fourth oxidation fan; 5. The first valve; 6. The second valve; 7. The third valve; 8. The fourth valve; 9. The oxidation air main pipe; 10. The connecting valve; 11. The first regulating valve; 12. The first flow meter; 13. The first cooling water nozzle; 14. The oxidation air duct of the first tower; 15. The second regulating valve; 16. The second flow meter; 17. The second cooling water nozzle; 18. The oxidation air duct of the second tower; 19. The cooling water main pipe; 20. The first cooling water regulating valve; 21. The second cooling water regulating valve; 22. The first oxidation air branch pipe; 23. The first tower; 24. The oxidation air duct network; 25. The jet hole; 26. The rectangular support beam; 27. The vertical open short pipe; 28. The second oxidation air branch pipe; 29. ​​The second tower; 30. The oxidation air spray gun; 31. The support inside the tower; 32. The agitator. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] See also Figure 1 , Figure 2 as well as Figure 3 , the utility model provides a technical solution:

[0024] A high-efficiency oxidation air system suitable for wet double-tower desulfurization, comprising a first oxidation fan 1, a second oxidation fan 2, a third oxidation fan 3, a fourth oxidation fan 4, a primary tower 23, an oxidation air duct network 24, a secondary tower 29 and an oxidation air spray gun 30, wherein the first oxidation fan 1, the second oxidation fan 2, the third oxidation fan 3, and the fourth oxidation fan 4 are all connected to an oxidation air main pipe 9, a connecting valve 10 is installed on the oxidation air main pipe 9, two oxidation air main pipes 9 are provided, and the two oxidation air main pipes 9 are respectively connected to one side of the primary tower 23 and the secondary tower 29, the oxidation air main pipe 9 is connected to the oxidation air duct 14 of the primary tower, the oxidation air duct 14 of the primary tower is connected to the cooling water main pipe 19, and the oxidation air duct 14 of the primary tower passes through a plurality of first oxidation fans. The chemical wind branch pipe 22 is connected to the oxidation wind duct network 24 in the first-level tower 23. A number of jet holes 25 with a size of Φ12 are opened obliquely below both sides of the oxidation wind duct network 24. A vertical open short pipe 27 is installed at the tail of the jet hole 25. A rectangular support beam 26 is provided at the bottom of the jet hole 25. The oxidation wind main pipe 9 on one side of the second-level tower 29 is connected to the oxidation wind duct 18 of the second-level tower. The oxidation wind duct 18 of the second-level tower is connected to the cooling water main pipe 19 through the second cooling water regulating valve 21 and the second cooling water nozzle 17. The oxidation wind duct 18 of the second-level tower is connected to the oxidation wind spray gun 30 in the second-level tower 29 through a number of second oxidation wind branch pipes 28. The oxidation wind spray gun 30 is provided with a tower support 31, and each of the oxidation wind spray guns 30 is installed on the agitator 32.

[0025] Furthermore, the first oxidation fan 1, the second oxidation fan 2, the third oxidation fan 3, and the fourth oxidation fan 4 are connected to the oxidation air main pipe 9 through the first valve 5, the second valve 6, the third valve 7, and the fourth valve 8 respectively.

[0026] Furthermore, a first regulating valve 11 and a first flow meter 12 are installed at the connection between the oxidation air main pipe 9 and the first-stage tower oxidation air pipe 14 .

[0027] Furthermore, a first cooling water regulating valve 20 and a first cooling water nozzle 13 are installed at the connection between the first-stage tower oxidation air duct 14 and the cooling water main pipe 19 .

[0028] Furthermore, a second regulating valve 15 and a second flow meter 16 are installed at the connection between the oxidation air main pipe 9 and the secondary tower oxidation air pipe 18 .

[0029] Example

[0030] The specific implementation of the above-mentioned high-efficiency oxidation wind system is as follows:

[0031] The installation depth of the oxidation air duct network of the first tower is selected by comprehensively considering the liquid level in the tower and the spray-gun oxidation air system of the second tower, so that the resistance of the oxidation air system of the first tower 23 and the second tower 29 is close;

[0032] Under the load condition of 67% to 100% of the unit, three oxidation fans and corresponding fan outlet valves are turned on, and the connecting valve 10 on the oxidation air main 9 is turned on. The oxygen consumption of each is calculated according to the inlet and outlet flue gas parameters of the first tower 23 and the second tower 29, and the regulating valve is adjusted. The corresponding cooling water regulating valve is adjusted according to the oxidation air volume of the first tower 23 and the second tower 29;

[0033] Under the load condition of 33% to 67% of the unit, open the two oxidation fans and the corresponding fan outlet valves, open the connecting valve 10 on the oxidation air main 9, calculate the oxygen consumption of each according to the inlet and outlet flue gas parameters of the first tower 23 and the second tower 29, adjust the regulating valve, and adjust the corresponding cooling water regulating valve according to the oxidation air volume of the first tower 23 and the second tower 29;

[0034] When the unit is under load conditions below 33%, open an oxidation fan and the corresponding fan outlet valve, open the connecting valve 10 on the oxidation air main 9, calculate the oxygen consumption of each according to the inlet and outlet flue gas parameters of the first tower 23 and the second tower 29, adjust the oxidation air regulating valves of the first tower 23 and the second tower 29, and adjust the corresponding cooling water regulating valves according to the oxidation air volumes of the first tower 23 and the second tower 29;

[0035] Under special circumstances, when the oxidation air systems of the primary tower 23 and the secondary tower 29 need to operate independently, ensure that at least one set of oxidation fans and outlet valves are opened on each side, close the connecting valve 10 on the oxidation air main 9, and adjust the corresponding cooling water regulating valve according to the oxidation air volume of the primary tower 23 and the secondary tower 29.

[0036] In the description of the present invention, it should be understood that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" 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 present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In addition, the terms "first", "second", "third" and "fourth" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first", "second", "third" and "fourth" may explicitly or implicitly include at least one of such features.

[0038] In the present utility model, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated 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, it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the utility model according to the specific circumstances.

[0039] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A high-efficiency oxidation air system suitable for wet double-tower desulfurization, comprising a first oxidation air fan (1), a second oxidation air fan (2), a third oxidation air fan (3), a fourth oxidation air fan (4), a primary tower (23), an oxidation air duct network (24), a secondary tower (29) and an oxidation air spray gun (30), wherein the first oxidation air fan (1), the second oxidation air fan (2), the third oxidation air fan (3) and the fourth oxidation air fan (4) are all connected to an oxidation air main pipe (9), a connecting valve (10) is installed on the oxidation air main pipe (9), and the oxidation air main pipe (9) is provided with two, and the two oxidation air main pipes (9) are respectively The oxidation air main pipe (9) is connected to the oxidation air duct (14) of the first tower, and the oxidation air duct (14) of the first tower is connected to the cooling water main pipe (19). The oxidation air duct (14) of the first tower is connected to the oxidation air duct network (24) in the first tower (23) through a plurality of first oxidation air branch pipes (22). A plurality of jet holes (25) with a size of Φ12 are opened obliquely below the two sides of the oxidation air duct network (24). A vertical open short pipe (27) is installed at the tail of the jet hole (25). A rectangular support beam (26) is provided at the bottom of the jet hole (25).

2. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 1, characterized in that: The oxidation air main pipe (9) on one side of the secondary tower (29) is connected to the secondary tower oxidation air pipe (18), and the secondary tower oxidation air pipe (18) is connected to the cooling water main pipe (19) via a second cooling water regulating valve (21) and a second cooling water nozzle (17).

3. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 2 is characterized in that: The secondary tower oxidation air duct (18) is connected to the oxidation air spray gun (30) in the secondary tower (29) through a plurality of second oxidation air branch pipes (28).

4. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 3 is characterized in that: The oxidation air spray gun (30) is provided with an inner tower support (31), and each oxidation air spray gun (30) is installed on a stirrer (32).

5. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 1 is characterized in that: The first oxidation fan (1), the second oxidation fan (2), the third oxidation fan (3), and the fourth oxidation fan (4) are connected to the oxidation air main pipe (9) via a first valve (5), a second valve (6), a third valve (7), and a fourth valve (8), respectively.

6. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 2 is characterized in that: A first regulating valve (11) and a first flow meter (12) are installed at the connection between the oxidation air main pipe (9) and the first tower oxidation air pipe (14).

7. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 6, characterized in that: A first cooling water regulating valve (20) and a first cooling water nozzle (13) are installed at the connection between the first-stage tower oxidation air duct (14) and the cooling water main pipe (19).

8. The high-efficiency oxidation air system suitable for wet double-tower desulfurization according to claim 4, characterized in that: A second regulating valve (15) and a second flow meter (16) are installed at the connection between the oxidation air main pipe (9) and the secondary tower oxidation air pipe (18).

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