A risk based heat exchanger analysis subject to fouling Part I: Performance evaluation

Heat exchangers operating in the power and process industries are fouled to a greater or lesser extent depending on surface temperature, surface condi tion, material of construction, fluid velocity, flow geometry and fluid com position. This fouling phenomenon is time-dependent and will result in a de crease in the thermal effectiveness of a heat exchanger. Once the thermal e ffectiveness decreases to a minimum acceptable level, cleaning of the equip ment becomes necessary to restore the performance. In this paper, we presen t a simple probabilistic approach to characterize various fouling models th at are commonly encountered in many industrial processes. These random foul ing growth models are then used to investigate the impact on risk-based the rmal effectiveness, overall heat-transfer coefficient and the hot- and cold -fluid outlet temperatures of a shell-and-tube heat exchanger. All the resu lts are presented in a generalized form in order to demonstrate the general ity of the risk-based procedure discussed in this paper. (C) 2000 Elsevier Science Ltd. All rights reserved.