Why Shut Down the Economizer Recirculation
There are several reasons for shutting down economizer recirculation during normal boiler operation. Primarily, the boiler needs a specific amount of water and pressure to function correctly. Excessive recirculation through the economizer can result in insufficient water in the water-cooled shell, which may cause the shell temperature to rise and even lead to tube ruptures. To prevent this risk and ensure safe operation, it is essential to close the economizer recirculation.
Secondly, shutting down the economizer recirculation can significantly increase boiler efficiency. During coal combustion, the exhaust gases released by the boiler carry substantial thermal energy. In conventional boiler operations, this energy often goes to waste. However, by closing the economizer recirculation, the thermal energy in these exhaust gases can be effectively captured and utilized by a waste heat boiler, thereby improving coal efficiency and achieving better energy savings.
How to Shut Down the Economizer Recirculation
Shutting down the economizer recirculation is not a simple task. Generally, it requires the following steps:
- Close Economizer Recirculation Before Shutdown
Before shutting down the boiler, it is necessary to first deactivate the economizer recirculation. Begin by stopping the hot air furnace fan, followed by shutting down the primary and secondary fan units. Next, turn off the cooling water supply to the air preheater, and finally, shut down the cooling tower.
- Close the Economizer After Shutdown
Once the boiler is shut down, the economizer should be turned off from the control room. The process generally involves several steps: first, close the boiler outlet valve, then shut down the deaerator, and finally, turn off the cooling water supply to the air preheater, among other required steps.
- Switching the Economizer During Normal Operation
If you need to switch the economizer during normal boiler operation, follow a specific procedure. Typically, first, close the economizer’s recirculation function before shutting down. Then, stop the hot air furnace fan and wait 10-15 minutes for the recirculation system to fully empty. Afterward, open the switching valve, start the economizer, and reopen the recirculation valve to restore its function.
In summary, closing the economizer recirculation can prevent tube rupture in the water-cooled shell and significantly enhance boiler efficiency. However, both shutting down and switching the economizer require attention to numerous details and should be performed following the correct procedures.
About Us
Shandong Bokk Tech is dedicated to solve the problem such as ash blockage, corrosion and excessive exhaust gas temperature in the tubular air preheater of small and medium-sized boilers. We primarily manufacture automatic cleaning devices for tubular air preheaters and corrosion-resistant heat pipes. Our products are widely used in the thermal power plants, chemical plants, new energy sector, etc.
We offer customized services to customers around the world, allowing us to adjust product dimensions and other specifications based on your specific needs, to improve air preheater heat efficiency.
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