The function of the air preheater is to use the heat of the flue gas to heat the boiler equipment. It is generally installed at the end of the convection flue. As one of the important components of modern boiler heat utilization, its heating surface is the bottom of the entire boiler unit. , is also another heating surface of the flue gas process. Generally, the air preheater includes regenerative, thermally conductive and heat pipe types, while the circulating fluidized bed boiler tubular air preheater discussed in the paper belongs to the thermally conductive type. The process of its action It is the transfer and exchange of heat through the evaporation and condensation of heat pipe liquid. The specific functions are mainly manifested in four aspects:
1. It can increase the stability of combustion. Because the air preheater has the function of preheating, the temperature of the combustion-supporting air, and the effect of strengthening the combustion, the combustion is sufficient and the combustion efficiency of the boiler is improved;
2. Reduce the exhaust gas temperature. Since the temperature of the economizer used in thermal power generation reaches 250 degrees Celsius during operation, it cannot cool the flue gas, and the role of the air preheater is to cool the waste heat of the flue gas. The conversion can effectively reduce the temperature of the flue gas, generally below 150 degrees Celsius, making full use of the waste heat of the flue gas and improving the energy utilization rate;
3. Reduce the metal loss of the equipment, because the high temperature air can increase the flue gas temperature in the furnace, increase the radiation in the furnace, and reduce the metal loss;
4. Drying function, hot air dries pulverized coal, etc., reduces the moisture in it, and improves the efficiency of pulverizing.