The simulation and validation of a run-around heat recovery system model are presented. The simulation procedure includes the prediction of coupling liquid flow rates for the particular set of operating conditions once the appropriate system, pump, and liquid pipeline characteristics are known. An existing run-around heat recovery system was instrumented and monitored from December 1990 to March 1991 to measure all the important temperatures, flow rates and pressure drops under a wide range of operating conditions. The measured output parameters are compared with equivalent results derived from a simulation model, where the measured input variables are used to generate these simulated values. The error in the simulation model is then established by comparing the measured and simulated heat rates using a relative error calculation. Typically, values for this relative error are less than +/- 5%. The resulting model can now be used for accurate design and simulation of the life-cycle cost savings using hourly weather data.

KEYWORDS: validating, run around coils, heat exchangers, heat recovery, calculating, monitoring, measuring, temperature, flow rate, pressure drop, operations, comparing, heat flow, accuracy, service life, costs