Method and device for controlling the number of pumps to be operated

摘要

In a system for controlling the flow rate of water supplied in a multi-pump water supply system which includes a pond or reservoir for the water, a first characteristic curve representing the cumulative values of predicted load flow rates over a period of time and a second characteristic curve representing the sum of the cumulative values and the capacity of the pond are generated. Operation routes restricted as to the number of pump change-over operations are then sought so that the routes pass through the region between the first and second characteristic curves and the gradient of the portion of each operation route is changed when the operation route crosses with the first or second characteristic curve. Among the operation routes sought, there is selected an optimum operation route which has the most suitable evaluation function from the point of view of energy consumption and efficiency. The pumps are then controlled in number in response to the selected operation route.