In an energy audit, the following information was obtained from the inspection of a boiler: Fuel: Rating (input) Output: Exhaust Temperature: Exhaust Gas Analysis on dry basis: CO 02 N2 Natural Gas 10 million (MM) Btu/hr Saturated Steam at 55 psig 450 F Calculate: 8.6% 5.6% Balance Assume 3% loss due to surface losses and blow-down. a - Fuel air ratio (assume that natural gas can be taken as methane) b - Mass flow rate of fuel and air c - Mass flow rate of steam generation if the feed water (water entering the boiler) is at 180 F. d - Maximum flame temperature that can be expected in the boiler? You may use an online calculator for this purpose. e - Boiler efficiency f- It is decided to recover heat from the exhaust by directing the feedwater through the heat exchanger to be installed on the exhaust stack, to cool the exhaust to 300 F. Calculate % of the energy saved by installing the heat exchanger (economizer). Submit your results along with a tech memo summarizing your results.