Sensitivity analysis of moving packed-bed heat exchanger models

A sensitivity analysis of moving packed-bed heat exchanger models is presented. A heat exchanger symmetric half-plate geometry based on the Gen 3 Particle Pilot Plant (G3P3) is meshed and solved using a conjugate heat transfer model. Seven independent variables are sampled at random within prescribed limits and the model is run for up to 64 different combinations of the input parameters. The overall heat transfer coefficient is output for each simulation and the Sobol index is calculated and used to compare sensitivity levels of the inputs. The analysis is performed in two parts to provide insight from both an overall design and optimization perspective in addition to an operational standpoint for an existing heat exchanger. The first key finding is that the overall heat transfer coefficient sensitivity is almost entirely dominated by the particle channel width. The second insight is that for an existing heat exchanger where the geometric parameters are fixed, the overall heat transfer coefficient prediction still has a significant level of uncertainty that can be limited by better characterizing the packed-bed void fraction.