Problem $5$: A combustor has a burning efficiency of $95\%$ when using light crude oil as fuel. Air enters the

combustor at a rate of $230k\frac{g}{s}$ and at a temperature of $350C.$ The specific heat of reaction for the light

crude oil is $43,200k\frac{J}{k}g.$ The required exit temperature of the combustor is $1100C.$ Determine the fuel

flow rate of the light crude oil in $(k\frac{g}{h}r).$ If the light crude oil is replaced by natural gas $(Q_R=51,000kJ.kg)$

and the combustor efficiency is improved to $98\%,$ what is the financial impact of the fuel change for $7,200$

hours of operation if the fuel prices are $($light crude oil $=0\mathrm{.}35S\frac{R}{k}g$ and, natural gas $=0\mathrm{.}43S\frac{R}{k}g).$