Effects of Leak Detection/Location on Underground Heat Distribution System (UHDS)Life Cycle Costs: A Probabilistic Model

摘要

Army maintenance costs for underground heat distribution systems (UHDSs) were$51.4 million in fiscal year 1989 (FY89). Leak location, an important UHDS maintenance element, is accomplished by using leak location techniques in various sequences, depending on the type of heat distribution system. This report presents a model to estimate the probable costs of leak detection in both direct buried (DB) prefabricated conduit and concrete shallow trench (ST) heat distribution systems, given the inherent uncertainty of available detection techniques. Techniques discussed include visual inspection, random search, bisection search, infrared thermography, tracer gas, and acoustic emission. The projected leak location/repair costs for each UHDS are calculated, and the effects of maintenance costs on operation costs as a result of these projections are discussed. Also discussed are the construction cost/maintenance cost trade-offs that occur when comparing DB and ST life cycle costs. Underground heat distribution system, life cycle costs.