Addition of heat?
Explain the following terms;
(i) critical radius of insulation.
(ii) economic lagging thickness.
An electric wire has a diameter of 1.3 mm and is to be covered with insulation 2.5 mm thick of thermal conductivity 0.35 W/mK. If the outside surface heat transfer coefficient is 15.0 W/m2K, calculate the critical radius of insulation. Would the addition of the insulation expect to increase or decrease the rate of heat transfer from the wire? Justify your answer.