CN-224230047-U - Plate type air preheater system for relieving low-temperature blockage and corrosion of rotary air preheater

Abstract

The application discloses a plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater, which relates to the field of heat energy and power engineering, overcomes the defect that the low-temperature section of the rotary air preheater is easy to corrode in the prior art, and mainly adopts the technical scheme that the plate type air preheater system for relieving the low-temperature blockage and corrosion of the rotary air preheater comprises a rotary air preheater and a plate type air preheater component which are connected in sequence, the air inlet of the heat exchange system is arranged at the air inlet of the rotary air preheater, the air outlet of the heat exchange system is arranged at the air outlet of the plate air preheater assembly, the air inlet and the air outlet of the plate air preheater assembly are provided with pressure difference transmitters, a plurality of mutually independent air channels are arranged in front of the air inlet of the plate air preheater assembly, a switch valve is arranged at the air channel, and the switch valve is used for controlling a plurality of valve plates for opening or closing the corresponding air channels. The application is mainly used for solving the problem that the low-temperature section of the rotary air preheater is easy to corrode.

Inventors

• HE HUAMING
• LEI RONG
• XIA XIN
• SHI HAOYUAN
• ZHANG YOUHONG
• Xie Hancong
• SU WEIHUANG
• ZHU MENGLI
• LIU DONGPING
• WANG GAI
• LU GANG
• YU GUANGCHAO
• XI XIANGDONG
• YU YINFEI

Assignees

• 浙江君华智慧物联科技有限公司

Dates

Publication Date

20260512

Application Date

20250429

Claims (9)

1. 1. The plate type air preheater system for relieving low-temperature blockage and corrosion of the rotary air preheater comprises the rotary air preheater and a plate type air preheater component which are sequentially connected, and is characterized in that an air inlet of the air preheater system is arranged at an air inlet of the plate type air preheater component, an air outlet is arranged at an air outlet of the rotary air preheater, an air inlet of the air preheater system is arranged at an air inlet of the rotary air preheater, an air outlet of the air preheater system is arranged at an air outlet of the plate type air preheater component, a pressure difference transmitter is arranged at the air inlet and the air outlet of the plate type air preheater component, a plurality of mutually independent air channels are arranged in front of the air inlet of the plate type air preheater component, and a switch valve is arranged at the air channel and is used for controlling a plurality of valve plates for opening or closing the corresponding air channels.
2. 2. The plate type air preheater system for relieving low-temperature blockage and corrosion of the rotary air preheater according to claim 1, wherein the plate type air preheater component comprises a first plate type air preheater and a second plate type air preheater, air sequentially flows through the air sides of the second plate type air preheater and the first plate type air preheater and is discharged through an air outlet of the rotary air preheater, and flue gas sequentially flows through the flue gas sides of the rotary air preheater and the first plate type air preheater and is discharged through a flue gas outlet of the second plate type air preheater.
3. 3. The plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater according to claim 2, wherein the smoke side of the first plate type air preheater is arranged below the smoke side of the rotary air preheater, and the smoke side of the second plate type air preheater is arranged below the smoke side of the rotary air preheater.
4. 4. The system of claim 2, wherein the air inlet of the plate air preheater assembly comprises an air inlet of a first plate air preheater and an air inlet of a second plate air preheater, and the air duct is arranged in front of the air inlet of the first plate air preheater and/or in front of the air inlet of the second plate air preheater.
5. 5. The plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater according to claim 1, wherein the plurality of valve plates controlled by the switch valve are used for closing corresponding air channels one by one when being closed.
6. 6. The panel air preheater system for reducing low temperature plugging and corrosion of a rotary air preheater according to claim 2, wherein the air side between said first and second panel air preheater is connected by a C-turn plenum.
7. 7. The system of claim 6, wherein the C-turn plenum is laterally remote from the air side of the rotary air preheater and a plurality of independent air ducts are provided at the C-turn plenum.
8. 8. The plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater according to claim 1, wherein the flue gas temperature of a flue gas outlet of the rotary air preheater is 150 ℃ or more.
9. 9. The system of claim 1, wherein the switching valve comprises a controller electrically connected to the differential pressure transmitter, such that when the differential pressure transmitter reaches a set threshold, the controller receives a signal to activate the switching valve to close the corresponding air duct.

Description

Plate type air preheater system for relieving low-temperature blockage and corrosion of rotary air preheater Technical Field The application relates to the field of heat energy and power engineering, in particular to a plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater. Background From the viewpoint of equipment operation condition analysis, as environmental standards are increasingly strict, coal-fired boilers are commonly equipped with a Selective Catalytic Reduction (SCR) denitration system and a wet desulfurization system. In the SCR denitration process, if ammonia escape is poorly controlled (the ammonia escape rate exceeds 3 ppm), escaped ammonia gas can react with SO 3 and water vapor in flue gas to generate ammonium bisulfate (NH 4HSO4) with strong viscosity. The melting point of ammonium bisulfate is 147 ℃, and the ammonium bisulfate is in a liquid state at the low-temperature section (120-140 ℃) of the rotary air preheater, is extremely easy to adhere to the surface of a heat exchange element to form dust accumulation and scale formation, so that a flue gas channel is blocked, the resistance of a system is increased, and the low-temperature corrosion is further aggravated. Meanwhile, the wet desulfurization system can lead the flue gas to carry a large amount of water vapor, raise the dew point temperature of the flue gas, increase the condensation risk of sulfuric acid vapor and accelerate the low-temperature corrosion process. In the prior art, although measures such as increasing the inlet air temperature of the air preheater, using corrosion resistant materials (e.g. enamel pipe, ND steel) are taken to alleviate the low temperature corrosion, limitations still exist. The high temperature of the air can reduce the heat efficiency of the system, the high cost of the corrosion-resistant material and the limited protection effect under specific working conditions can not fundamentally solve the problem of corrosion in the low temperature section. Disclosure of Invention The application provides a plate type air preheater system for relieving low-temperature blockage and corrosion of a rotary air preheater, which aims to overcome the defect that the low-temperature section of the rotary air preheater is easy to corrode in the prior art, and can solve the problem that the low-temperature section of the rotary air preheater is easy to corrode. In order to achieve the aim, the plate type air preheater system for relieving low-temperature blockage and corrosion of the rotary air preheater comprises the rotary air preheater and a plate type air preheater component which are sequentially connected, wherein an air inlet of the heat exchange system is arranged at an air inlet of the plate type air preheater component, an air outlet of the heat exchange system is arranged at an air outlet of the rotary air preheater, a flue gas inlet of the heat exchange system is arranged at a flue gas inlet of the rotary air preheater, a flue gas outlet of the heat exchange system is arranged at a flue gas outlet of the plate type air preheater component, differential pressure transmitters are arranged at the flue gas inlet and the flue gas outlet of the plate type air preheater component, a plurality of mutually independent air channels are arranged in front of the air inlet of the plate type air preheater component, and a switch valve is arranged at the air channel and is used for controlling a plurality of valve plates for opening or closing the corresponding air channels. The preferred scheme among the above-mentioned technical scheme is that the partial region of current rotary air preheater, that is the low temperature section converts into board-like air preheater subassembly, because board-like air preheater's structure is comparatively compact, and the flue gas passageway is relatively more regular, and the air current distributes evenly, is difficult for appearing local vortex and dead zone, can effectively avoid flue gas to stagnate in certain region, has reduced the possibility that the sulphuric acid steam that leads to because of flue gas dwell time overlength condenses and corrodes, consequently replace the board-like air preheater low temperature section can increase certain corrosion resistance by board-like air preheater subassembly. The operation principle of the application is that the pressure difference transmitter is arranged at the smoke inlet and the smoke outlet of the plate air preheater component, when the pressure difference transmitter reaches a set threshold value due to accumulation of ammonium bisulfate in the smoke channel, the corresponding air channel can be closed by the switch valve, so that the entry of air is reduced or isolated, the heat exchange degree of smoke is reduced, at the moment, the smoke channel temperature of the plate air preheater component and the smoke channel temperature of the rotary heat exchanger are bo