Heat exchanger design procedures rely on a series of correlations to estimate heat transfer coefficients, pressure drops, costs, etc. Each correlation is characterized by uncertainties, i.e. it returns an approximate value of the variable that it aims at predicting. This paper studies how sensitive the total cost evaluation is to these uncertainties for shell-and-tube heat exchangers. A variance decomposition approach is used to calculate the total effect of each uncertain variable. Three test cases are studied for which the most influential uncertainties were found to be those on the correlations for evaluating the purchase cost and the shell side heat transfer coefficient. Probability distributions of the total cost are presented and exhibit a large variance of the total cost. The impact of the cost of energy was also investigated, which revealed that uncertainty on energy cost had a smaller total effect than that of other variables.
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