| 摘要 |
PURPOSE:To operate an operating means with minimum energy loss by always deciding unequivocally the number of operating means which are operated in parallel according to the increase/decrease of load on the basis of the upper limit value of an available load range for the number of selected operating means. CONSTITUTION:A tank 1 stores a fluid W at a fixed level L and contains an input pipeline 2 and a discharge pipeline 3. Plural pump devices 5 constitute the operating means between the pipeline 2 and an introduction pipeline 4. These devices 5 are controlled by controllers 6. The operations of devices 5 are selected by an operating unit number switching means 7 via a total load controller 9 and an arithmetic means 10. If the present total using load is set at A with four working operating means, the number of operating means are increased by one when the load increases from A1 and reaches the operable upper limit value A2 on a line B4. At the same time, an action point also moves to a point A3 on a line B5. If the load is reduced, the working means are decreased by one and then switched to the original four units at a point A4. |
