System for increasing efficiency of steam generator system having a regenerative air preheater

A method for increasing the efficiency of a steam generator system including a boiler and an air preheater;

• the boiler producing a flow of flue gas containing SO3;
• the air preheater including an air inlet, a flue gas outlet defining a cold end and a flue gas inlet and an air outlet defining a hot end, and a plurality of conventional heat exchange element basket assemblies;
• the flow of flue gas being received by the flue gas inlet, carried through the heat exchange element basket assemblies, and discharged from the flue gas outlet, whereby the flow of flue gas creates a pressure drop across the air preheater;
• at least a portion of the SO3 carried in the flue gas forming an acid and accumulating in the cold end of the air preheater, the rate of acid accumulation depending on the amount of SO3 carried in the flue gas, whereby the pressure drop across the air preheater increases from a maximum allowable clean condition pressure drop to a maximum allowable dirty condition pressure drop over an operating cycle of the steam generator system;
• the method comprising the steps of:
• determining a reduced rate of acid accumulation achievable by injecting an SO3 neutralizing additive material into the flue gas;
• calculating a new maximum allowable clean condition pressure drop based on the reduced rate of acid accumulation;
• creating a modified heat exchange element basket having an increased heat transfer efficiency compared to the conventional heat exchange element basket assembly and a maximum allowable clean condition pressure drop substantially equal to the calculated new maximum allowable clean condition pressure drop;
• replacing the conventional heat exchange element basket assemblies with modified heat exchange element basket assemblies;
• and
• adding the additive material to the flue gas when the boiler is operating.