Q$7(14-22$ and $14-23)(15$ marks$)$

A $70\%$ efficient compressor delivers air to a pneumatic system at $690$ kPa gage and $6$ standard $\frac{m^3}{m}in.$ The efficiency of the electric motor driving the compressor is $90\%,$ and the compressor operates $4000$ hours per year. If the cost of electricity is $$\frac{0\mathrm{.}10}{k}Wh,$ determine the cost of electricity per year.

If the compressor is required to provide air at $790$ kPa gage to offset a $100$ kPa pressure loss in the pipelines due to friction and an additional $1\mathrm{.}5$ standard $1\frac{m^3}{m}in$ of air to compensate for air leakage, what is the additional cost of electricity per year due to these two types of energy losses?

Ans: $$18,040/$yr $($plus $$6,280/$yr due to losses$)$