The steam requirements of a manufacturing facility are being met by a boiler whose rated heat input is 5.5 x 106 Btu/h. The combustion efficiency of the boiler is measured to be 0.65. After tuning up the boiler, the combustion efficiency rises to 0.75. The boiler operates 4000 hours a year intermittently. Take the unit cost of energy to be $4.35/106 Btu. Assuming the same heat output for before and after the tunning:.

A2-m rigid tank initially contains saturated water vapor at 100 kpa. the tank is connected to a supply line through a valve. steam is flowing in the supply line at 600 kpa and 300 c. the valve is opened, and steam is allowed to enter the tank until the pressure in the tank reaches the line pressure, at which point the valve is closed. a thermometer placed in the tank indicates that the temperature at the final state is 200°c. determine (a) the mass of steam that has entered the tank (b) the amount of heat transfer.