SETT OCH ANORDNING FOR BEHOVSBEROENDE REGLERING AV EN PUMPANORDNINGS TRANSPORTMENGD

摘要

The invention relates to a pumping system for supplying fluid at a variable delivery rate in accordance with demand. The system includes one pump having a variable delivery rate and one or more auxiliary pumps arranged in parallel therewith, each having a fixed delivery rate. The variable delivery pump operates over a predetermined control range between minimum and maximum rates. Each fixed delivery rate pump has on and off operating modes with the on mode delivery rate being at the maximum delivery rate of the variable delivery pump. A control unit for operating the pumps matches the pump delivery with the demand. The control unit functions to set the variable delivery pump at its minimum delivery rate when operation of the fixed delivery pump is initiated during upward demand control and for setting it at its maximum delivery rate when operation of the fixed delivery pump is terminated during downward demand control.