A Semi Analytical Solution for the Optimum Insulation Thickness Problem

The problem of optimizing the thickness of insulation installed on large hot vessels has been solved using a semi-analytical method. Unlike the previous studies, the derived mathematical expressions for the optimum thickness and total cost of burned fuel and insulating material has been formulated in a general form which facilitates their application to any fuel and insulation characteristics and life time of the system. Moreover, the system analysis took into consideration the normally expected annual increase in fuel price. Also an expression for the net saving in fuel cost-due to the installation of insulation has been derived. The results showed that the required optimum insulation thickness increases as the lifetime of a vessel and fuel price based on the results it is recommended to: (i) Estimate the virtual lifetime of a vessel to calculate the corresponding correct optimum thickness of insulation, (ii) Install an insulation which is thicker somewhat (say 10%) than the optimum one to compensate for both the expected annual increase in fuel price and the natural deterioration in the thermal and mechanical characteristics of the insulation material. 4 figs