Patent ID: 8690542
Filing Date: 2014-04-08
Classification: F04D,F25C

Abstract:
1. An arrangement for starting up a pump system, the pump system comprising a pump for generating a liquid flow, an electrical drive disposed to actuate the pump, and a pressure sensor disposed to measure liquid pressure at a flow output of the pump, the arrangement comprising a control unit arranged to detect, during a first one of successive temporal control intervals while the pump is starting, whether there is an increase in the liquid pressure, wherein the control unit is further arranged to detect, during each of the successive temporal control intervals after the first one of the successive temporal control intervals and in response to a situation in which no increase in the liquid pressure was detected during the preceding one of the successive temporal control intervals, whether the liquid pressure has increased, the control unit is further arranged to detect, during each of the successive temporal control intervals after the first one of the successive temporal control intervals and in response to a situation in which an increase in the liquid pressure was detected during the preceding one of the successive temporal control intervals, whether the liquid pressure has increased, the control unit is further arranged to respond to detection of no increase in the liquid pressure in one of the successive temporal control intervals, after the first one of the successive temporal control intervals, by increasing a rotation speed of the pump during an immediately following one of the successive temporal control intervals, the control unit is further arranged to respond to detection of an increase in the liquid pressure in one of the successive temporal control intervals, after the first one of the successive temporal control intervals, by keeping unchanged the rotation speed of the pump during an immediately following one of the successive temporal control intervals, and the rotation speed of the pump at the beginning of each of the successive temporal control intervals after the first one of the successive temporal control intervals is at least partly determined by the rotation speed of the pump at the end of the previous one of the successive temporal control intervals.