APPLICATION OF TRANSIENT ANALYSIS METHODOLOGY TO QUANTIFY THERMAL PERFORMANCE OF HEAT-EXCHANGERS

A transient testing technique is developed to evaluate the thermal per formance of industrial-scale heat exchangers. A Galerkin-based numeric al method with a choice of spectral basis elements to account for spat ial temperature variations in heat exchangers is developed to solve th e transient heat exchanger model equations. Testing a heat exchanger i n the transient state may be the only viable alternative where convent ional steady-state testing procedures are impossible or infeasible. Fo r example, this methodology is particularly suited to the determinatio n of apparent fouling levels in component cooling water system heat ex changers in nuclear power plants. The head load on these so-called com ponent coolers under steady-state conditions is too small to permit me aningful testing An adequate heat load develops immediately after a re actor shutdown when the exchanger inlet temperatures are highly time-d ependent. The application of the analysis methodology is illustrated h erein with reference to an in-situ transit testing carried out at a nu clear powerplant. The method, however, is applicable to any transient testing application.