기액이상류시의 펌프특성실험에 관한 기초연구

Abstract

In a general centrifugal pump, if it is operated for a two-phase flow the activity of the impeller usually degrades and occasionally losses its function.

However, the effect of break down of centrifugal pump due to entrained air has not been clarified yet. Thus, air-water two-phase flow experimental apparatus was installed to acquire basic data. This paper tries to analyze the single-phase flow and air-water two-phase flow characteristics through this air-water two-phase flow experimental apparatus. The pump rpm and the shaft torque are measured by rpm sensor and torque sensor. The casing is made up with transparency acrylic for confirmation the flow patterns. According to void fraction, mass and shape of impeller, the pump characteristics under a single-phase flow were measured. The test pump's maximum rpm, head, kW are 1,750, 15m and 1.5kW, respectively. The performance results of a single-stage closed-type centrifugal pump satisfied reappearance and reliance. Also, in a single-phase flow, compare to semi-open type impeller, closed-type impeller has superior and efficiency. But in air-water two-phase flow, the rate of decrease of efficiency and head decreases.