摘要 |
A method and controller for operating pumps wherein each pump is modelled by a QH model indicating a high-efficiency region, a high-H region and a high-Q region and a rotational speed limit. A controller dynamically maintains a current set of operating pumps and controls their rotational speed (n). In steady-state operation, wherein the pumps operate in the high-efficiency region and below the rotational speed limit, all pumps of the current set are controlled together. If the pumps operate in the high-Q region or beyond the speed limit, a new pump is added to the current set, started and brought to a speed that produces flow. A balancing operation (12-3) follows the pump addition operation, wherein the speed of the pumps of the current set are adjusted for equal heads. If the pumps operate in the high-H region, a pump is removed from the current set of pumps. |