TRANSIENT HYDRAULIC PERFORMANCE OF A CENTRIFUGAL PUMP DURING RAPID STARTING PERIOD

摘要

An analysis of the fluid in a centrifugal pump has been made under unsteady conditions. A theoretical calculation of the head is established to predict the transient characteristics. During the centrifugal pump starting period, the experimental study has been made on the transient hydraulic performance for the varied opening degree of the valve. The changes of instantaneous rotational speed, head and flow-rate with time are measured. The results of the experiments must be revised. Because a part of the head is offered to accelerating the fluid in the pipeline during starting, which is unable to be measured by the pressure-sensor. The theoretical calculations are analyzed and compared with the corresponding experimental results. The revised head is identical with the steady-estimated one basically. According to the test results, during the starting period for 0.5 second, the transient characteristics of the centrifugal pump are identical with the steady characteristics basically. The transient head of a centrifugal pump is the sum of the steady head and the unsteady one.