Manufacturing method of pressurized sealing system suitable for rotary air preheater

1. The utility model relates to the technical field of air preheaters, in particular to a pressurized sealing system suitable for rotary air preheaters.

Background technique

2. The current rotary air preheater sealing device is mainly divided into two categories, one is the mechanical contact sealing device, which is mainly divided into multiple sealing technology, adjustable sealing technology, flexible sealing technology, gap self-compensation technology and quarter warehouse Structural technology, etc.; the other type is the extractable dredging and sealing system device.

3. At present, the mechanical contact sealing technology is more commonly used. After the sealing system is installed, serious friction may occur between the sealing plate and the fan-shaped plate, and the sealing plate is prone to wear and fall off, resulting in an increase in the driving current of the air preheater , The operation is stable and reliable, which increases the maintenance cost of the unit; and the air preheater leakage rate cannot be maintained at a relatively ideal level for a long time. Often in the later period of the overhaul period, the air preheater leakage rate increases significantly, which seriously affects the operation of the unit. Economy. The fixed sealing technology has a compact structure and a low leakage rate, but the sealing plate is prone to frequent replacement due to corrosion and wear, and the maintenance cost is high. In addition, when the boiler load is low, the air leakage rate of the air preheater is still large; if it encounters unexpected situations (such as abnormal flue gas temperature), the rotor of the air preheater is likely to jam and cause abnormal shutdown of the boiler, which will cause the power plant Great economic loss. Adjustable sealing technology is currently one of the more common sealing methods in China. It uses sensors to monitor the deformation state of the rotor at regular intervals, and then the actuator adjusts the height of the fan-shaped plate according to the feedback signal to reduce the air leakage gap and reduce the air leakage rate. However, this technology has a large gap measurement error, poor tracking of the thermal state of the fan-shaped plate, and a large amount of system maintenance and workload.

4. Withdrawable drainage and sealing technology is to drain and recover the air that leaks to the flue gas side and send it to the furnace for reuse to achieve the purpose of reducing air leakage. Grooming and sealing technology generally sends the leaking air in the sealing area into the secondary air, which will increase the primary air leakage rate, resulting in a significant reduction in the effective utilization rate of the primary fan, further reduction in the margin of the primary fan, and a significant reduction in the adjustment margin. As a result, the output of the pulverizing system is insufficient, which affects the load capacity of the unit, and the leakage air from the high pressure head is sent to the secondary air, which will reduce its energy grade. Therefore, the dredging sealing technology does not have the energy-saving effect.

Please contact us at zhang@pride-cnc.com