Numerical Research on Flow Characteristics in a Plate-type Falling Film Heat Exchanger for a LiBr/H2O Absorption Heat Pump

An optimum designed plate-type falling film heat exchanger is the key technique to scale down the size of a LiBr/H2O absorption heat pump. Flow characteristics have the largest impact on the performance of a plate-type falling film heat exchanger. However, there is no research on falling-film flow characteristics of LiBr solution on the corrugated plate in vacuum atmosphere. Numerical flow models based on a plate-type falling film heat exchanger were constructed with 2-D and full 3-D spatial and temporal resolution using the Volume of Fluid technique. Flow characteristics of horizontal columns with different degrees of arc were successfully modelled with 2-D spatial model and the optimum arc degree is found. The falling-film flow patterns under different Reynolds number are thoroughly analyzed with full 3-D spatial model.