Predicting the impact of heat exchanger fouling in power systems

•A model is presented to predict power systems performance under fouled conditions.•The relative change in both system and performance parameters are studied.•By using the Buckingham Pi theorem, important dimensionless groups are identified.•The performance degradation of heat exchangers is found to be logarithmic.

In this work, a prediction equation is proposed that determines performance parameters of fouled power systems as long as heat transfer in the two-phase region is dominant. Fouling was simulated by degrading the overall conductance. Dimensional analysis was used to reduce the problem to seven Pi groups. Since behavior found in endoreversible systems is often imitated by real systems, the endoreversible case was used for initial demonstration followed by a simulated Rankine cycle. Using an example problem, during degradation of the overall conductance, the observed parameters were found to behave logarithmically. Prediction was done by combining data under specified conditions for finite thermal capacitances. This type of model can offer benefit through saving both money and time by decreasing required number of experiments and/or simulations as well as in planning better cleaning schedules.