Design and optimization study of heat exchanger based on distributed parameter model

In the process of design heat exchanger, the accuracy is not enough for lumped parameter model when dealing with large temperature difference, phase change, localized high heat flux and so on. Hence, a computational model based on the distributed parameter was established in this paper to calculate the heat transfer and flow resistance of heat exchangers. In this method, the core was discretized into a number of units. The parameters of each unit were calculated using an equation group establishing through energy conservation. The outlet temperatures of the previous unit were taken as the inlet parameters of the next one. The fluid thermos-physical properties were updated in time when the unit was calculated. Compared with lumped parameter model, it performs a higher accuracy for distributed parameter model against with experimental data. Moreover, the heat transfer and flow resistance for different configurations were calculated using distribution parameter models. The results showed that hydraulic diameter was negatively related to heat transfer characteristics and positively related to flow resistance. This study can provide a reference for the design and optimization of heat exchangers.