k$=15($W$)/($mK$),$ Di$=5$cm$,$Do$=6$cm$,$ and L$=10$m $-30$ deg C with a flow rate of $0\mathrm{.}15$ kg$/($s$).$ Determine

the insulation thickness for the pipe using a material with k$=0\mathrm{.}95($W$)/($mK$),$ to keep

the liquid ammonia's exit temperature at $-20$ deg C$,$ while maintaining the insulated

pipe outer surface temperature at $20$ deg C$.$