Decision method of thermoeconomic life of piping insulation

Proposes the exposed coefficient of heat insulation, which describes the change of the effect of heat insulation. Based on the same rule of determining the replacement period of heat insulation layer, i.e. thermoeconomic life, presents the mathematical model suitable for unitary systems and compound systems.  An example shows that replacing heat insulation at the ending of thermoeconomic life can improve effectively economic benefits of piping operation.