Horizontal-tube falling film evaporators (HFE) are widely used in the thermal desalination industry due to their increasing advantages. The liquid distribution state of the tube bundle directly affects the heat transfer performance of the evaporator. To improve the uneven liquid distribution among tube rows, a balanced distribution structure (BDS) that can balance the liquid distribution state in the HFE was proposed. A general distributed parameter model was built to describe the steady-state

performance of the HFE with and without the BDS, taking into account different liquid distribution of odd and even rows. The model is applied to simulate the multieffect distillation (MED) system of a desalination power plant, and the numerical results show a good arrangement with the operating results. The results indicate that the BDS slightly improves the overall heat transfer performance and the total evaporation rate. This work and the designed BDS certainly could help in the design and optimization of HFE for desalination processes.