Patent Number: 
Section: claims

1. A turbine equipment, comprising:a compressor for compressing a working fluid;a turbine driven to rotate by the working fluid;a circulating flow path for circulating the working fluid at least between the compressor and the turbine;a bypass flow path for bypassing the working fluid from a delivery side to a suction side of the compressor;a bypass valve for controlling a flow rate of the working fluid flowing through the bypass flow path;a motor for driving to rotate the compressor and the turbine by way of a speed reducing portion in starting; anda controller configured to control the turbine equipment bycontrolling the motor to increase a rotational speed by driving to rotate the compressor and the turbine by way of the speed reducing portion;receiving a signal from a load detector configured to detect a load applied to the speed reducing portion; andcontrolling the bypass valve, wherein the controller controlling the bypass valve includescalculating a bypass flow rate based on the detected load and a predetermined value;calculating a bypass flow rate which will prevent surging of the compressor from being brought about based on a pressure ratio between the suction side and the delivery side of the compressor, and a corrected rotational speed of the compressor calculated based on a temperature of the working fluid delivered to the turbine;selecting the bypass flow rate having a larger flow rate from the bypass flow rates calculated by the calculating steps; andcontrolling the bypass valve to increase a flow rate of the working fluid bypassed from the delivery side to the suction side of the compressor when an absolute value of the detected load is equal to or smaller than an absolute value of the predetermined value and reducing the flow rate of the bypassed working fluid when the absolute value of the load is equal to or larger than the absolute value of the predetermined value, but ensuring that the flow rate of the bypassed working fluid does not decrease below the selected bypass flow rate to thereby prevent surging of the compressor. 2. A turbine equipment as claimed in claim 1, wherein the compressor is a low pressure compressor and the bypass flow path is a first bypass flow path in which a first bypass valve is mounted and is configured to bypass working fluid from the delivery side to the suction side of the low pressure compressor, the turbine equipment further including a high pressure compressor. 3. A turbine equipment as claimed in claim 2, further comprising a second bypass flow path in which a second bypass valve is mounted, the second bypass flow valve being configured to bypass working fluid from a delivery side of the high pressure compressor to the suction side of the low pressure compressor. 4. A turbine equipment as claimed in claim 2, wherein the low pressure compressor, the high pressure compressor and the turbine are mounted on a common shaft to which the motor is drivingly connected through the speed reducing portion. 5. A method of controlling a turbine equipment during starting, the turbine equipment including a compressor for compressing a working fluid, a turbine driven to rotate by the working fluid, a circulating flow path for circulating the working fluid at least between the compressor and the turbine, a bypass flow path for bypassing the working fluid from a delivery side to a suction side of the compressor, a bypass valve for controlling a flow rate of the working fluid flowing through the bypass flow path, a motor for driving to rotate the compressor and the turbine by way of a speed reducing portion in starting and a controller configured to control the turbine equipment, the method including:controlling the motor by increasing the rotational speed of the motor which increases the rotational speed of the compressor and turbine by driving the compressor and the turbine by way of the speed reducing portion;receiving a signal from a load detector configured to detect a load applied to the speed reducing portion;calculating a bypass flow rate based on the detected load and a predetermined value;calculating a bypass flow rate which will prevent surging of the compressor from being brought about based on a pressure ratio between the suction side and the delivery side of the compressor, and a corrected rotational speed of the compressor calculated based on a temperature of the working fluid delivered to the turbine;selecting the bypass flow rate having a larger flow rate from the bypass flow rates calculated by the calculating steps and controlling the operation of the bypass valve to open the valve to increase a flow rate of the working fluid bypassed from the delivery side to the suction side of the compressor when an absolute value of the detected load is equal to a smaller than absolute value of the predetermined value and reducing the flow rate of the bypassed working fluid by closing the valve when the absolute value of the load is equal to or larger than the absolute value of the predetermined value, but ensuring that the flow rate of the bypassed working fluid does not decrease below the selected bypass flow rate to thereby prevent surging of the compressor. 6. A method as claimed in claim 5, in which the predetermined value of the load is selected to reduce the risk of damage to the speed reducing portion which could occur under low load conditions.