A method of controlling a heating medium flow rate and a steam flow rate in an integrated solar combined cycle electric power generation system wherein the integrated solar combined cycle electric power generation system includes a steam turbine, a gas turbine, a waste heat recovery boiler configured to generate steam by utilizing waste heat of said gas turbine and supply steam thus generated to said steam turbine, a heating medium supply system having a heat exchanging device for generating steam to be supplied to said steam turbine and configured to supply said heat exchanging device with a heating medium for heating water therein by collected solar thermal energy, a steam supply passage interconnecting said heat exchanging device and a steam pipe of said waste heat recovery boiler for supplying steam to said waste heat recovery boiler, a steam flow rate detecting device and a first steam flow rate controlling device, which are provided on said steam supply passage, and a control device capable of controlling a flow rate of steam passing through said steam supply passage by means of said first steam flow rate controlling device based on a result of detection by said steam flow rate detecting device, and wherein said heating medium supply system including a heating system configured to heat a heating medium by sunlight, a heat exchanging device configured to heat feedwater by means of the heating medium supplied thereto from said heating system, a heating medium supply passage for circulating the heating medium to said heating system and to said heat exchanging device, a first heating medium temperature detecting device, a heating medium flow rate detecting device and a first heating medium flow rate controlling device, which are provided on said heating medium supply passage at respective locations between an outlet of said heating system and an inlet of said heat exchanging device, and a control device capable of controlling an operation of said first heating medium flow rate controlling device based on results of detections by said first heating medium temperature detecting device and said heating medium flow rate detecting device, the method comprising:
- continuously or intermittently calculating a value of thermal energy to be supplied to said heat exchanging device by the heating medium from a temperature and flow rate of the heating medium to be supplied to said heat exchanging device;
- controlling the flow rate of the heating medium to be supplied to said heat exchanging device so that a rate of increase with time in the supply energy does not exceed a predetermined value;
- continuously or intermittently detecting a supply flow rate of steam to be supplied from said heat exchanging device to said waste heat recovery boiler;
- and
- controlling the supply flow rate of steam to be supplied from said heat exchanging device to said waste heat recovery boiler so that a rate of increase with time in the supply flow rate of steam does not exceed a predetermined value.