| 摘要 |
At the time of start of operation when a temperature of a water medium becomes equal to or higher than a shell temperature of a high temperature-side compressor 31 by a predetermined temperature difference or more, a law temperature-side compressor 21 is started after a high temperature-side compressor 31 is started. Therefore, since the shell temperature of the high temperature-side compressor 31 rises in a state where a discharge pressure of the high temperature-side compressor 31 is restrained from rising, condensation of a refrigerant in the shell of the high temperature-side compressor 31 is suppressed, and a discharge amount of oil is reduced. Therefore, it is possible to suppress consumption of standby electricity required for heating, by a heater, shell of the high temperature-side compressor 31 which is under suspension, to prevent the high temperature-side compressor from being damaged, and to secure reliability of energy-saving performance of the apparatus. |
