REFRIGERATING SYSTEM AND METHOD FOR CONTROLLING COMPRESSOR SETS IN SUCH A REFRIGERATING SYSTEM

摘要

A refrigerating system (2) according to the invention comprises at least one refrigerant circuit (4) having a set of compressors (6, 8, 10), each of said compressors (6, 8, 10) being operable at least one compressor power stage, a control unit for the set of compressors (6, 8, 10), a liquefied (12), an evaporator also forming a heat exchanger (14), refrigerant conduits connecting the set of compressors (6, 8, 10), the liquefied (12), and the heat exchanger (14), and circulating a refrigerant, and a pressure sensor (16) arranged between the heat exchanger (14) and the set of compressors (6, 8, 10) sensing the refrigerant pressure; a cold carrier circuit (22) having a cold carrier pump (36), a cold consumer region (24), cold carrier conduits connecting the cold carrier pump (36), the heat exchanger (14) and the cold consumer region (24) and circulating a cold carrier, which is refrigerated in the heat exchanger (14), and a temperature sensor (26, 28) sensing the cold carrier temperature. The control unit for the set of compressors (6, 8, 10) is configured such that, in case of the temperature sensor (26, 28) sensing a too high cold carrier temperature, it prevents turning on additional compressor power stages, if the refrigerant pressure is below a first critical value (pSUBmin/SUB + ?pi) and decreases, and it switches off at least one running compressor power stage, if the refrigerant pressure falls below a second critical value (pSUBmin/SUB - ?p2).