CO Online Monitoring Technology of Power Station B

CO Online Monitoring Technology of Power Station Boiler

 (Datang Togtoh Power Plant) 

  Due to various kinds of fire coal used in power station boiler in China, oxygen contents controlled during the actual operation often deviate from optimal oxygen contents, causing lower heat efficiency and increased NOx emission. CO concentration is highly sensitive to total air volume. In particular, minor change to oxygen contents will make CO concentration change sharply near the critical point. There is certain relationship between CO contents and combustibles in fly ash and heat loss due to exhaust gas. The method of CO monitoring can be used to operate boiler under relatively low excess air without causing local oxygen deficit and improve boiler efficiency without triggering scorification and hot corrosion because of local oxygen deficit inside furnace.

  In November 2012, CO-controlled combustion technology was installed by our Company at Datang International Togtoh Power Plant. CO controlled combustion adjustment can improve safety and economy of boiler operation, prevent boiler combustion from generating large quantities of CO and find out the uneven combustion at both sides inside furnace in time, all of which cannot be achieved in time simply by O2 monitoring at the air-preheater inlet of current power station boiler. To this end, it is quite necessary to conduct CO controlled combustion adjustment and optimization of power station boiler.

  It is proven in the field test that heat efficiency of boiler can be increased by 0.4% and NOx emission can be decreased by 20% when CO control-based combustion adjustment and optimization technology is adopted. In the CO test, minimum oxygen contents required for boiler operation have been determined and economical and safe boiler operation has not been affected by significantly increased CO emission.