A flue gas dehumidification and dehydration device and method for a thermal power plant

Abstract

The present application discloses a device and method for dehumidifying and dehydrating flue gas in a thermal power plant, which relates to the field of separation technology, and comprises: a spray tower, on which a flue gas inlet interface, a circulating water outlet and a circulating water inlet are arranged; a cooling device, which is fixedly arranged inside the spray tower, and the cooling device is correspondingly arranged at a position above the flue gas inlet interface, and the cooling device is connected to the circulating water inlet; a smoke exhaust pipe, which is arranged above the spray tower, and a defogger is arranged in the smoke exhaust pipe; the defogger comprises: a fixed frame, which is fixedly arranged in the smoke exhaust pipe, and a regulating fan is fixedly arranged in the fixed frame; a defogger screen assembly, which is fixedly arranged below the fixed frame; a cooling circulation system, which comprises an air cooler and a circulating water tank, wherein the air cooler, the circulating water inlet, the circulating water outlet and the circulating water tank are sequentially connected to provide a more efficient technical solution for cooling and separation.

Description

Technical Field

[0001] The present application relates to the field of separation technology, and in particular to a device and method for dehumidifying and dehydrating flue gas in a thermal power plant. Background Art

[0002] The working principle of the flue gas water lifting system is mainly based on the principle of phase change condensation of wet saturated water vapor under different partial pressures. In the process of thermal power generation, the combustion of coal will produce high-temperature flue gas. After the flue gas undergoes purification processes such as wet desulfurization, it will contain a large amount of water vapor. The process components of the flue gas water lifting system include a flue gas system, a cooling device, a cooling circulation system, a cold source system, and a pH adjustment system. The sulfur dioxide concentration of the flue gas entering the condensation tower is controlled by the flue gas system to avoid excessive sulfur dioxide concentration that increases the operating load of the flue gas water lifting system; the saturated flue gas is directly in contact with the low-temperature circulating water for heat exchange and cooling to achieve condensation and water collection. The cooled flue gas is discharged after the water mist is removed by the dust and mist remover.

[0003] However, the corresponding high-temperature flue gas transfers heat with the spray droplets during the cooling process, where the surface of the spray droplets is the interface for mass and heat transfer between the flue gas and water. The larger the heat transfer interface, that is, the smaller the spray droplet particle size, the better the heat transfer effect. However, if the spray droplet particle size is too fine, it will be carried by the flue gas and cannot be captured by the demister, affecting the overall cooling efficiency.

[0004] Therefore, it is necessary to provide a flue gas dehumidification and dehydration device and method for a thermal power plant to solve the problems raised in the above background technology. Summary of the invention

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solution: a flue gas dehumidification and dehydration device for a thermal power plant, comprising:

[0006] A spray tower, on which a smoke inlet interface, a circulating water outlet and a circulating water inlet are arranged;

[0007] A cooling device is fixedly arranged inside the spray tower, and the cooling device is correspondingly arranged above the flue gas inlet interface, and the cooling device is connected to the circulating water inlet;

[0008] A smoke exhaust pipe is arranged above the spray tower, and a demisting device is arranged in the smoke exhaust pipe;

[0009] The demisting device comprises:

[0010] A fixed frame, fixedly arranged in the smoke exhaust pipe, and a regulating fan is fixedly arranged in the fixed frame;

[0011] A demisting screen assembly is fixedly arranged below the fixing frame;

[0012] The cooling circulation system comprises an air cooler and a circulating water tank, wherein the air cooler, the circulating water inlet, the circulating water outlet and the circulating water tank are connected in sequence.

[0013] Furthermore, preferably, the cooling circulation system further comprises a regulating tank, which is a component of a dosing system and is used to add alkali to adjust the pH of the cooling circulation system.

[0014] Further, as a preference, a spraying section and a demisting section are respectively provided on the spray tower, the spraying section corresponds to the temperature-reducing cooling device, and the demisting section corresponds to the demisting device.

[0015] Further, preferably, the temperature-reducing and cooling device comprises a plurality of evenly distributed spray pipe groups, a single spray pipe group consists of a main pipe and a spray head, and a plurality of spray heads are arranged under the single main pipe.

[0016] Furthermore, preferably, the spray heads are densely arranged on the main duct, and a plurality of spray openings with adjustable calibers are provided at the lower end of the spray heads, and the spray openings are fan-shaped for spraying droplets, and multiple layers of fan-shaped droplets overlap in the space where the spray pipe group is located to cover the entire internal cross-section of the spray tower.

[0017] Further, preferably, the demisting screen assembly comprises a circulating atomizing pipe and a vibrating baffle, the circulating atomizing pipe is connected to the circulating water inlet, and the circulating atomizing pipe is periodically bent and twisted to pass through the vibrating baffle.

[0018] Further, preferably, the vibration baffles are arranged in parallel in plurality, and the vibration baffles are fixedly connected to the fixing frame, and the vibration baffles are loosely connected at the position where they are sleeved on the circulating atomization pipe.

[0019] Furthermore, preferably, a plurality of atomization ports are evenly distributed on the circulating atomization pipe, and the atomization ports open toward the vibration baffle, and the vibration baffle is hollow.

[0020] A method for dehumidifying and dehydrating flue gas in a thermal power plant comprises the following steps:

[0021] Ⅰ. The high-temperature flue gas generated by burning coal is first desulfurized through a purification process to control the sulfur dioxide concentration of the flue gas entering the spray tower later;

[0022] II. The circulating water is cooled in the air cooler by air cooling, and the cooled circulating water is supplied to the temperature reduction cooling device and the demisting device through the circulating water inlet;

[0023] III. The high-temperature flue gas after desulfurization is transported to the spray tower through the flue gas inlet interface, and is successively passed through the cooling device and the demisting device for heat exchange, condensation and dehumidification. A plurality of the spray pipe groups form multi-layer fan-shaped droplets that overlap and cover the entire internal section of the spray tower. The saturated flue gas is directly in contact with the low-temperature circulating water for heat exchange and cooling to achieve condensation and water collection. The atomization port sprays out droplets of smaller particle size through the atomization port to further process the flue gas after heat exchange and condensation by the cooling device. The vibration partition transmits and adjusts the vibration generated by the operation of the fan and the circulating water in the circulating atomization pipe, and promotes the recovery and adsorption of dust and water in the flue gas through sound waves to complete the entire separation process.

[0024] Ⅳ. After being treated, the high-temperature flue gas is discharged through the smoke exhaust pipe after its humidity and temperature are reduced.

[0025] Compared with the prior art, the present application provides a device and method for dehumidifying and dehydrating flue gas in a thermal power plant, which has the following beneficial effects:

[0026] The droplets sprayed from the atomizing port in the present application have a smaller particle size, that is, have a larger mass transfer and heat transfer interface, and the circulating atomizing tube sprays droplets through the atomizing port to further process the flue gas after heat exchange and condensation treatment by the cooling device, and uses droplets with smaller particle sizes to provide a larger mass transfer and heat transfer interface to efficiently reduce the flue gas temperature, thereby promoting further separation of moisture in the flue gas, and the atomizing port is directly opposite to the vibrating baffle, and the droplet travel is small. The vibrating baffle is attached to transmit and adjust the vibration generated by the fan and circulating water in the circulating atomizing tube, and promotes the recovery and adsorption of dust and water in the flue gas through sound waves. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings.

[0028] Figure 1 The figure is a schematic diagram of the overall structure of a flue gas dehumidification and dehydration device for a thermal power plant.

[0029] Figure 2 The present invention is a schematic diagram of the structure of a spray tower portion of a flue gas dehumidification and dehydration device in a thermal power plant.

[0030] Figure 3 The present invention is a schematic diagram of the structure of a cooling device for a flue gas dehumidification and dehydration device in a thermal power plant.

[0031] Figure 4 The present invention is a schematic diagram of the structure of a demisting device for a flue gas dehumidification and dehydration device in a thermal power plant.

[0032] Figure 5 The present invention is a schematic diagram of the structure of a demisting screen assembly of a flue gas dehumidification and dehydration device in a thermal power plant.

[0033] In the figure: 1. Spray tower; 11. Smoke inlet interface; 12. Circulating water outlet; 13. Circulating water inlet; 2. Cooling device; 21. Spray pipe group; 211. Main duct; 212. Spray head; 3. Smoke exhaust pipe; 4. Demisting device; 41. Fixed frame; 42. Adjusting fan; 43. Demisting screen assembly; 431. Circulating atomizing pipe; 432. Vibrating baffle; 433. Atomizing port; 5. Cooling circulation system; 51. Air cooler; 52. Circulating water tank; 53. Adjusting tank; 6. Spray section; 7. Demisting section. DETAILED DESCRIPTION

[0034] See also Figure 1-Figure 5 In an embodiment of the present application, a flue gas dehumidification and dehydration device for a thermal power plant comprises:

[0035] A spray tower 1 is provided with a smoke inlet interface 11, a circulating water outlet 12 and a circulating water inlet 13;

[0036] A cooling device 2 is fixedly arranged inside the spray tower 1, and the cooling device 2 is correspondingly arranged above the flue gas inlet interface 11, and the cooling device 2 is connected to the circulating water inlet 13;

[0037] A smoke exhaust pipe 3 is arranged above the spray tower 1, and a demisting device 4 is arranged in the smoke exhaust pipe 3;

[0038] The demisting device 4 comprises:

[0039] A fixed frame 41 is fixedly arranged in the smoke exhaust pipe 3, and a regulating fan 42 is fixedly arranged in the fixed frame 41;

[0040] A demisting screen assembly 43 is fixedly arranged below the fixing frame 41;

[0041] The cooling circulation system 5 includes an air cooler 51 and a circulating water tank 52, wherein the air cooler 51, the circulating water inlet 13, the circulating water outlet 12, and the circulating water tank 52 are connected in sequence. Specifically, the air cooler 51 adopts an air cooling form, and the circulating water tank 52 adopts a high-level water tank, taking into account the subsequent dosing and mixing buffer time, as well as the safety buffer time of the circulating pump on the circulating water tank 52.

[0042] As a preferred embodiment, the cooling circulation system 5 also includes a regulating tank 53. The regulating tank 53 is a component of a dosing system and is used to add alkali to adjust the pH of the cooling circulation system 5. Specifically, the flue gas discharged from the desulfurization tower is water-saturated flue gas, as well as a small amount of other pollutants such as sulfur dioxide. The pH of the circulation system is adjusted by adding sodium hydroxide through the dosing system, and the amount of dosing is determined according to the total amount of inlet sulfur dioxide with a certain margin.

[0043] It should be explained that the use of recycled water and the buffer storage time are controlled by the cooling circulation system 5 .

[0044] As a preferred embodiment, the spray tower 1 is respectively provided with a spray section 6 and a demisting section 7, the spray section 6 corresponds to the cooling device 2, and the demisting section 7 corresponds to the demisting device 4. Specifically, the flue gas is sequentially treated by the spray section 6 and the demisting section 7 for dehumidification and dewatering, and the water is recovered.

[0045] In this embodiment, Figure 3 The cooling device 2 includes a plurality of evenly distributed spray pipe groups 21 , wherein a single spray pipe group 21 is composed of a main pipe 211 and a spray head 212 , and a plurality of spray heads 212 are arranged under the single main pipe 211 .

[0046] As a preferred embodiment, the spray heads 212 are densely arranged on the main duct 211, and a plurality of spray openings with adjustable calibers are provided at the lower end of the spray heads 212. The spray openings are fan-shaped for spraying droplets, and multiple layers of fan-shaped droplets overlap in the space where the spray pipe group 21 is located to cover the entire internal cross-section of the spray tower 1.

[0047] It should be explained that the spray coverage, spray flow rate per unit area and spray droplet particle size are controlled by adjusting the spray head 212 to control the uniform distribution of the liquid side flow field; the total coverage of the spray layer is not less than 400%, and the corresponding spray droplet particle size is 1200μm-1500μm, and the saturated flue gas is in direct contact with the low-temperature circulating water for heat exchange and cooling to achieve condensation and water collection.

[0048] As a preferred embodiment, the demisting screen assembly 43 includes a circulating atomizing pipe 431 and a vibrating baffle 432 . The circulating atomizing pipe 431 is connected to the circulating water inlet 13 , and the circulating atomizing pipe 431 is periodically bent and twisted to pass through the vibrating baffle 432 .

[0049] As a preferred embodiment, the vibration baffles 432 are arranged in parallel in multiple numbers, and the vibration baffles 432 are fixedly connected to the fixing frame 41 , and the vibration baffles 432 are loosely connected at the position where they are sleeved on the circulating atomization pipe 431 .

[0050] As a preferred embodiment, a plurality of atomization ports 433 are evenly distributed on the circulating atomization pipe 431 , and the atomization ports 433 open toward the vibration baffle 432 , and the vibration baffle 432 is hollow.

[0051] It should be explained that the droplets sprayed from the atomizing port 433 have a smaller particle size, that is, they have a larger mass transfer and heat transfer interface, and the circulating atomizing pipe 431 sprays droplets through the atomizing port 433 to further process the flue gas after heat exchange and condensation treatment by the cooling device 2, and uses droplets with smaller particle sizes to provide a larger mass transfer and heat transfer interface to efficiently reduce the flue gas temperature, thereby promoting further separation of moisture in the flue gas, and the atomizing port 433 is directly opposite to the vibrating baffle 432, and the droplet travel is small. The vibrating baffle 432 transmits the vibration generated by the operation of the regulating fan 42 and the circulating water in the circulating atomizing pipe 431, and promotes the recovery and adsorption of dust and water in the flue gas through sound waves.

[0052] A method for dehumidifying and dehydrating flue gas in a thermal power plant comprises the following steps:

[0053] Ⅰ. The high-temperature flue gas generated by burning coal is first desulfurized through a purification process to control the sulfur dioxide concentration of the flue gas subsequently entering the spray tower 1;

[0054] II. The circulating water is cooled in the air cooler 51 by air cooling, and the cooled circulating water is supplied to the temperature reduction cooling device 2 and the demisting device 4 through the circulating water inlet 13;

[0055] III. The high-temperature flue gas after desulfurization is transported to the spray tower 1 through the flue gas inlet interface 11, and is successively passed through the cooling device 2 and the demisting device 4 for heat exchange, condensation and dehumidification. A plurality of the spray pipe groups 21 form multi-layer fan-shaped droplets that overlap and cover the entire internal section of the spray tower 1. The saturated flue gas is directly in contact with the low-temperature circulating water for heat exchange and cooling to achieve condensation and water collection. The atomization port 433 sprays out droplets of smaller particle size through the atomization port 433 to further process the flue gas after heat exchange and condensation treatment by the cooling device 2. The vibrating partition 432 transmits the vibration generated by the operation of the regulating fan 42 and the circulating water in the circulating atomization pipe 431, and promotes the recovery and adsorption of dust and water in the flue gas through sound waves, completing the entire separation process.

[0056] IV. After the humidity and temperature of the treated high-temperature flue gas are reduced, it is discharged through the smoke exhaust pipe 3.

[0057] What has been described above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes within the technical scope disclosed in the present application according to the technical solution and application concept of the present application, which should be covered by the protection scope of the present application.

Claims

1. A flue gas dehumidification and dehydration device for a thermal power plant, characterized in that: include: A spray tower (1) is provided with a smoke inlet interface (11), a circulating water outlet (12) and a circulating water inlet (13); A cooling device (2) is fixedly arranged inside the spray tower (1), and the cooling device (2) is arranged correspondingly at a position above the smoke inlet interface (11), and the cooling device (2) is connected to the circulating water inlet (13); A smoke exhaust pipe (3) is arranged above the spray tower (1), and a demisting device (4) is arranged in the smoke exhaust pipe (3); The demisting device (4) comprises: A fixed frame (41) is fixedly arranged in the smoke exhaust pipe (3), and an adjustable fan (42) is fixedly arranged in the fixed frame (41); A demisting screen assembly (43) fixedly disposed below the fixing frame (41); A cooling circulation system (5) comprises an air cooler (51) and a circulating water tank (52), wherein the air cooler (51), a circulating water inlet (13), a circulating water outlet (12), and the circulating water tank (52) are connected in sequence; The demisting screen assembly (43) comprises a circulating atomizing pipe (431) and a vibrating baffle (432); the circulating atomizing pipe (431) is connected to the circulating water inlet (13), and the circulating atomizing pipe (431) is periodically bent and twisted to penetrate the vibrating baffle (432); A plurality of vibration baffles (432) are arranged in parallel, and the vibration baffles (432) are fixedly connected to the fixed frame (41), and the vibration baffles (432) are loosely connected at the position where they are sleeved on the circulating atomization pipe (431); A plurality of atomization ports (433) are evenly distributed on the circulating atomization pipe (431), and the atomization ports (433) open toward the vibration baffle (432), and the vibration baffle (432) is hollow.

2. A flue gas dehumidification and dehydration device for a thermal power plant according to claim 1, characterized in that: The cooling circulation system (5) further comprises a regulating tank (53), which is a component of the dosing system and is used to add alkali to regulate the pH of the cooling circulation system (5).

3. A flue gas dehumidification and dehydration device for a thermal power plant according to claim 1, characterized in that: A spraying section (6) and a demisting section (7) are respectively arranged on the spray tower (1); the spraying section (6) corresponds to the temperature-reducing cooling device (2), and the demisting section (7) corresponds to the demisting device (4).

4. The device for dehumidifying and dehydrating flue gas in a thermal power plant according to claim 1, characterized in that: The temperature reduction and cooling device (2) comprises a plurality of spray pipe groups (21) arranged evenly, wherein a single spray pipe group (21) is composed of a main pipe (211) and a spray head (212), and a plurality of spray heads (212) are arranged under the single main pipe (211).

5. A flue gas dehumidification and dehydration device for a thermal power plant according to claim 4, characterized in that: The spray heads (212) are densely arranged on the main pipe (211), and a plurality of spray openings with adjustable calibers are provided at the lower ends of the spray heads (212). The spray openings are fan-shaped for spraying droplets, and multiple layers of fan-shaped droplets overlap and cover the entire internal cross-section of the spray tower (1) in the space where the spray pipe group (21) is located.

6. A method for dehumidifying and dehydrating flue gas in a thermal power plant, which uses a flue gas dehumidification and dehydration device for a thermal power plant as claimed in any one of claims 1 to 5, characterized in that: The steps include: Ⅰ. The high-temperature flue gas generated by burning coal is first desulfurized through a purification process to control the sulfur dioxide concentration of the flue gas that subsequently enters the spray tower (1); II. The circulating water is cooled by air cooling in the air cooler (51), and the cooled circulating water is supplied to the temperature reduction cooling device (2) and the demisting device (4) through the circulating water inlet (13); III. The high-temperature flue gas after desulfurization treatment is transported to the spray tower (1) through the flue gas inlet interface (11), and is successively passed through the cooling device (2) and the demisting device (4) for heat exchange, condensation and dehumidification. Multiple layers of fan-shaped droplets are formed through multiple spray pipe groups (21) to overlap and cover the entire internal cross-section of the spray tower (1). The saturated flue gas is directly in contact with the low-temperature circulating water for heat exchange and cooling to achieve condensation and water collection, and is sprayed out from the atomization port (433). The circulating atomization pipe (431) sprays droplets of smaller particle size through the atomization port (433) to further process the flue gas after heat exchange and condensation treatment by the cooling device (2). The vibrating baffle (432) transmits the vibration generated by the operation of the regulating fan (42) and the circulating water in the circulating atomization pipe (431), and promotes the recovery and adsorption of dust and water in the flue gas through sound waves, thereby completing the entire separation process. IV. After being treated, the high-temperature flue gas is discharged through the smoke exhaust pipe (3) after its humidity and temperature are reduced.

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