Because the flue gas temperature of power plant boiler air preheater of General higher and higher exhaust temperature of boiler efficiency, insufficient drying capacity of coal pulverizing system, long running, it is not economic. This is the preheater of general common problems, through the power plant inspection, you can see the preheater exhaust temperatures are high mainly because of:
1) serious design defects, such as boiler design parameters of analysis for heater selection calculation of negligence, wrong choice of heat transfer components sheet caused preheater and preheater type conditions. This is the main reasons of preheater's heat capacity is insufficient.
2) because of poor manufacturing quality, heater heat element has a strict size requirements, small differences in the geometry will also cause heater heat tianrang, so, at the time of manufacture due to the heat transfer component thickness changes, internal dimensions of difference between the components are first mate influence of preheater's heat capacity. This is the main reasons of preheater's heat capacity is insufficient.
3) leakage of coal pulverizing system is too large, excessive air leakage of coal pulverizing system, resulting into reduced organized air preheater, preheater caused high exhaust gas temperature.
4) bottom increased air leakage, principles of milling system, is the result of the organized air preheater reduced.
5) other reasons.