Ice storage chiller, Semi-hermetic single screw compressor, Large capacity
In China, the air conditioning equipment is rapidly in popular with economic development and improvement of standard of life. As a result, ratio of the electrical consumption by the air conditioning equipment is continuously increasing, and the lack of electricity at day time or the remaining of electricity at night time is becoming a problem. Ice storage technology is one of the methods to moderate the peak demand and is used widely. Ice storage is the technology that ice will be generated in the night time and the ice will be used in the day time for air conditioning. This will enable to flatten the demand of electricity between day time and night time. In China, the large capacity ice storage chiller is required in the market, therefore we developed the large capacity semi-hermetic single screw compressor which has high efficiency at cooling mode in the day time as well as at ice storage mode in the night time for the ice storage chiller from 500 up to 900USRT. This compressor is the largest capacity semi-hermetic single screw compressor in the world with the capacity of 490USRT at the ice storage mode and 730USRT at the cooling mode. For this design, the internal volume ratio was optimized for both the operation of ice storage and cooling mode. In addition, as for the critical speed which would be an issue in the development of the large compressor, the bearing location was optimized to avoid the resonance with the rotating speed. Consequently, COP of 3.90 at ice storage mode and COP of 4.83 at cooling mode were achieved. We believe that we can contribute to the environment protection with the high efficient air conditioning equipment by using this compressor.