Method for operating multi-phase compressor especially for refrigerating plants uses computer-calculated speed combinations for comparing ideal value and actual value of cold water header temperature for selecting right combination

摘要

Computer-calculated speed combinations which correspond to each maximum degree of efficiency are recorded by a memory programmable control in a two-dimensional table and at predetermined time intervals which depend on operating points the ideal value and the actual value of the cold water header temperature are compared. When the ideal value deviates from the control variable the pressure ratio of the plant is tested and a new speed combination is selected. In the event of a constant pressure ratio depending on the deviation of the ideal value from the control variable in each line of the table the preceding and next speed combination is controlled or with a change in the pressure ratio in the relevant column the preceding or next combination is controlled.