Simulation on the dynamic pressure and flow of the seawater desalination axial piston pump

The axial piston pump used as a high pressure pump is one of the most important component in small and medium scale Sea Water Reverse Osmosis (SWRO) desalination projects. The pressure and flow ripple is an important factor which impacts the noise level of the pump. The axial piston pump for SWRO desalination uses seawater as its working media and the fluid properties of seawater are obviously different from mineral oil. In order to accurately simulate the dynamic pressure and flow of the pump, the special properties of seawater have to be considered. For this reason, the variational fluid properties of mineral oil and seawater were simulated and the results were compared. The model which describes the dynamic pressure and flow was presented. The pressure and flow characters of a single cylinder and a swash plate axial piston pump with five pistons were simulated using this model. From the simulation results, the delivery pressure and flow ripple when taking seawater as working medium are greater than the oil one if the geometry and boundary conditions are same. In order to reduce the pressure and flow ripple, the overlap angle of the portplate when taking seawater as working medium should be small.