Abstract: The present invention provides a control device for detecting an abnormal operation state of a compressor in a parallel refrigerator. The control device is a control device for a refrigerator that includes a plurality of compressors connected in parallel, and detects occurrence of surging and occurrence of droplet suction on the basis of a deviation between values of currents flowing through electric motors that is configured to drive each of the plurality of compressors, and an operation point indicated by the air volume and the compression ratio of the plurality of compressors.

Abstract: The purpose of the present invention is to provide: a turbo compressor which is provided with an open impeller and has the minimal gap between the shroud and the impeller such that efficiency is improved and the safe operating region is enlarged; and a turbo chiller using the same. The turbo compressor is provided with an open impeller with a shroud provided on the side of a casing, and the rotary shaft is supported by a radial magnetic bearing and a magnetic thrust bearing. The turbo compressor is provided with a control unit that comprises: a load calculating means that calculates the axial thrust load generated by the pressure distribution of the compressor; and an axial support position control means that controls a gap between the impeller and the shroud to be a target gap by varying, on the basis of the axial thrust load, the axial support position of the rotary shaft due to the magnetic thrust bearing.

Abstract: To provide a control device of a refrigerating cycle, a heat source device, and a control method therefor which are capable of realizing a stable low-load operation without using a hot gas bypass pipe. A centrifugal chiller includes a compressor compressing a refrigerant; a condenser condensing the refrigerant compressed by the compressor; an expansion valve expanding a liquid refrigerant delivered from the condenser; an evaporator evaporating the refrigerant expanded by the expansion valve; and a control device (10).

Abstract: The present invention has an object to suppress an overshoot in the outlet temperature of a heat medium. A heat source machine controlling apparatus includes a computing unit and a set temperature changing unit. The computing unit calculates a load change rate using a predetermined arithmetic expression. The set temperature changing unit determines whether or not the load change rate calculated by the computing unit exceeds a predetermined threshold value. In the case where the load change rate exceeds the predetermined threshold value, the set temperature changing unit changes a set chilled water outlet temperature so as to suppress a change in a chilled water outlet temperature.

Abstract: The present invention has an object to suppress an overshoot in the outlet temperature of a heat medium. A heat source machine controlling apparatus includes a computing unit and a set temperature changing unit. The computing unit calculates a load change rate using a predetermined arithmetic expression. The set temperature changing unit determines whether or not the load change rate calculated by the computing unit exceeds a predetermined threshold value. In the case where the load change rate exceeds the predetermined threshold value, the set temperature changing unit changes a set chilled water outlet temperature so as to suppress a change in a chilled water outlet temperature.

Abstract: Provided is a heat source system that includes two heat source devices connected in series to a heat medium and can be efficiently operated. A heat source system (1) reduces the temperature of chilled water that is guided from a cooling load and has a predetermined return temperature Tr, to a predetermined supply temperature Ts, and supplies the chilled water to the cooling load. The heat source system (1) includes: a second centrifugal chiller (TR2) that reduces the temperature of the chilled water from the return temperature Tr to an intermediate temperature T2; a first centrifugal chiller (TR1) that reduces the temperature of the chilled water that has been reduced to the intermediate temperature T2 by the second centrifugal chiller (TR2), to the supply temperature Ts; and a control unit (9) that variably sets the intermediate temperature T2.

Abstract: The purpose of the present invention is to provide: a turbo compressor which is provided with an open impeller and has the minimal gap between the shroud and the impeller such that efficiency is improved and the safe operating region is enlarged; and a turbo chiller using the same. The turbo compressor is provided with an open impeller with a shroud provided on the side of a casing, and the rotary shaft is supported by a radial magnetic bearing and a magnetic thrust bearing. The turbo compressor is provided with a control unit that comprises: a load calculating means that calculates the axial thrust load generated by the pressure distribution of the compressor; and an axial support position control means that controls a gap between the impeller and the shroud to be a target gap by varying, on the basis of the axial thrust load, the axial support position of the rotary shaft due to the magnetic thrust bearing.

Abstract: Provided is a heat source system that includes two heat source devices connected in series to a heat medium and can be efficiently operated. A heat source system (1) reduces the temperature of chilled water that is guided from a cooling load and has a predetermined return temperature Tr, to a predetermined supply temperature Ts, and supplies the chilled water to the cooling load. The heat source system (1) includes: a second centrifugal chiller (TR2) that reduces the temperature of the chilled water from the return temperature Tr to an intermediate temperature T2; a first centrifugal chiller (TR1) that reduces the temperature of the chilled water that has been reduced to the intermediate temperature T2 by the second centrifugal chiller (TR2), to the supply temperature Ts; and a control unit (9) that variably sets the intermediate temperature T2.