Improves the economical efficiency of operation of the pressure rise device and the analogous equipment the manner

摘要

PURPOSE: To prevent unnecessary pressure increase and reduce the dimension of a tank by operating a pump periodically between a speed approaching a nominal speed and a speed approaching zero. CONSTITUTION: When fluid is discharged or fetched from a pressure increasing device in a range of a target fetch amount or an amount above that amount, a pump is operated with a nominal speed in a normal state within a range of maximum pump efficiency. When fluid is discharged or fetched from a pressure increasing device in an amount lower than the target fetch amount, the pump is operated reciprocally in an abnormal state between the operation in a range of maximum pump efficiency of the nominal speed and the operation with the minimum speed and minimum energy consumption.