Design of a centrifugal pump for liquid fuel pumping application.

摘要

This thesis studied the conventional and un-conventional design method of centrifugal pump of a liquid fuel to raise a low-pressure fuel supply to the pressure required for the combustion system. In addition, the operating processes of the current automotive fuel pump systems were analyzed. From this study, the feasibility in the replacement of automotive fuel pumps by the centrifugal pump was clarified.; The fuel property requirements are: Density (ρ = 770 kg/m 3), Viscosity (μ = 0.001 N-sec/m2). The duty points are: Head (H = 50.36m), Low flow rate (Q = 3.9*10−5 m 3/s), High rotational speed (N = 9000rpm). The “conventional pump design method” resulted in a centrifugal pump with a very poor theoretical efficiency, η = 7%. Because of the poor performance, an “unconventional pump design method” has been carried out and the theoretical efficiency have been significantly improved, η = 54.15%.; Modifications of pump geometry in un-conventional design method were manipulated to optimize the pump performance. In the first case, the theoretical optimal pump efficiency is highest, η = 65.5942%, when the number of blades is four and the exit blade angle is β₂ = 90°. In the second case, the theoretical optimal pump efficiency is η = 65.0498%, when the number of blades is four and the exit blade angle is β₂ = 70°.