Thermal resistance in corrugated plate heat exchangers under crystallization fouling of calcium sulfate (CaSO₄)

In a water heating system, the performance of the corrugated plate heat exchangers (PHEs) is often degraded by crystallization fouling due to the precipitation of insoluble salts on the heat transfer surface. In this study, the fouling resistance in corrugated PHEs was measured and analyzed according to CaSO₄ concentration, flow velocity, inlet temperatures of the solution and hot water, and corrugation angle of the plate. In addition, the asymptotic fouling resistance and asymptotic fouling period of PHEs were analyzed by varying the operating and geometric conditions of PHEs. A new correlation for the CaSO₄ crystallization fouling resistance was developed in terms of the asymptotic fouling resistance and asymptotic fouling period. The present correlation yielded satisfactory predictions with a mean absolute deviation of 4.8% from the measured data.