| 摘要 |
An object is to provide a turbo-refrigeration-unit control device capable of achieving stable operation and reducing the amount of refrigerant. Provided is a control device for controlling a turbo refrigeration unit (1) that includes a centrifugal compressor (2), a first-non-refrigerant pump (12) for supplying a first non-refrigerant, a condenser (3) that performs heat exchange between the first non-refrigerant and a refrigerant, an expansion valve (5) that expands the refrigerant, a second-non-refrigerant pump (16) for supplying a second non-refrigerant, an evaporator (7) that performs heat exchange between the second non-refrigerant and the refrigerant, a bypass circuit (17) that is used to inject part of the refrigerant from a discharge port (2B) of the centrifugal compressor (2) into a suction port (2A) of the centrifugal compressor (2), and a bypass-circuit control valve (18) that controls the flow rate of the refrigerant. When the turbo refrigeration unit (1) is started-up, the expansion valve (5) is controlled so as to be closed, the first-non-refrigerant pump (12) and the second-non-refrigerant pump (16) are operated, the centrifugal compressor (2) is started-up, and then the degree-of-opening of the bypass-circuit control valve (18) is controlled such that the temperature difference between a suction saturation temperature at the centrifugal compressor (2) and an outlet temperature of the second non-refrigerant becomes equal to or less than a predetermined temperature difference. |
