UNCERTAINTY ANALYSIS OF HEAT-EXCHANGER THERMAL DESIGNS USING THE MONTE-CARLO SIMULATION TECHNIQUE

The Monte Carlo simulation technique for determining uncertainties of the thermal parameters needed in designing heat exchangers is discussed. Parameters such as the outside diameter D(o), thickness t and thermal conductivity k are assumed to have Gaussian distributions, while the heat-transfer coefficients h(i) and h(o) are considered to follow normal, log-normal and Weibull forms of distribution. An illustrative example is presented. The overall heat-transfer coefficient U obtained from the simulation is found to have a distribution that is well approximated by the Weibull model. Using the Weibull distribution of U, the additional percentage area is calculated for 80 and 99% confidence levels (CLs). The proposed approach of design analysis incorporates realistic risks associated with uncertainties of the parameters.