A stainless-steel pipe (thermal conductivity 15=W/[m K]) is being used to transport
heated oil at. The inside temperature of the pipe is 120°C. The pipe has an inside
diameter of 5 cm and is 1 cm thick. Insulation is necessary to keep the heat loss from
the oil below 25W/m length of the pipe. Due to space limitations, only 5 cm thick
insulation can be provided. The outside surface temperature of the insulation must be
above 20°C (the dew point temperature of surrounding air) to avoid condensation of
water on the surface of insulation. Calculate the thermal conductivity of insulation that
will result in minimum heat loss while avoiding water condensation on its surface