低比速度遠心ポンプのバランスホール径が性能へ及ぼす影響

抄録

We will introduce research results on high performance of low speed centrifugal pump.in this paper Disk friction loss is one of the major causes of performance degradation of low specific speed centrifugal pumps. Numerical flow analysis was performed with balance hole diameter of 7.1, 5.0, 3.5, 2.5 and 1.8 mm in order to investigate the influence of balance hole diameter giving leakage flow from the back shroud clearance. As the balance hole diameter decreases, the circumferential velocity ratio in the back shroud clearance decreases, so it is not suitable as a disk friction reduction method. Because the head coefficient increased and the shaft power coefficient decreased, the efficiency increased and the maximum efficiency was achieved in 1.8 mm, so it is effective to reduce the balance hole diameter as a method for improving the performance of the low specific speed centrifugal pump .