The Study of Guide Vanes on Submersible Pump

Because the structure of submersible pump is special, and common guide vane is a factor effecting low efficiency, those guide vanes design method is different from ones of common axial flow pump and mixed flow pump. This paper introduces the design methods of guide vane on submersible pump. To improve the total performance, submersible pump structure, hydraulic performance, diffusion and friction loss are considered comprehensively when the meridian plane of guide vane is designed. The coefficient of diffusion on meridian plane should be larger than the recommended value and limited to avoid heavy flow separation. The guide vane number is bigger and meridian length of guide vane is shortened. For example, the number of guide vane can be nine or eleven, even thirteen when impeller blade number is four. Bigger number of guide vane makes the short guide vane placed on smaller diameter and avoids flow passage diffused more. On the other hand, smaller diameter will decrease pump dimension, weight, and production cost. To Balance the recycled energy and loss energy, outlet angle of guide vane should be reduced suitable. The angle should be 90 degree if completely recycling the rotating flow energy, but outlet angle should be larger than 90 degree if considering finite cascade. Those two angles will bring large diffusion of flow passage, large diffusion loss and flow friction force. Since the diffusion loss counts heavier percent of hydraulic loss, the angle should be reduced, such as 70 degree. That smaller angle doesn’t recycle completely the rotating energy, but hydraulic loss is decreased, and the efficiency of pump is higher instead. The test testifies that the efficiency of submersible pump designed by those above measures can reach 88%.