(40 pts) A power plant boiler is being designed to transfer 430x106 kJ/hour of thermal power to the working fluid. The boiler is to be fired by natural gas (assume methane properties) with 20% excess air. The stack gases from the plant are to be maintained at or above a temperature that exceeds the dew point of the combustion products by at least 150 C (so that water vapor will not condense in the stack and cause corrosion problems). The fuel is preheated to 80 C, and the air is preheated to 200 C. What mass flow rates of methane and air will be required? (40 pts) A power plant boiler is being designed to transfer 430x106 kJ/hour of thermal power to the working fluid. The boiler is to be fired by natural gas (assume methane properties) with 20% excess air. The stack gases from the plant are to be maintained at or above a temperature that exceeds the dew point of the combustion products by at least 150 C (so that water vapor will not condense in the stack and cause corrosion problems). The fuel is preheated to 80 C, and the air is preheated to 200 C. What mass flow rates of methane and air will be required