System design and installation of screw chiller
Global climate warming has become a growing threat to the survival and development of mankind, pointing to the urgent need for achieving carbon peak and carbon neutrality. Improving the energy efficiency of the present industrial equipment is one of the significant approaches. Because of the widespread use and huge power consumption of heating, ventilating and air conditioning systems in commercial buildings, a small improvement in the efficiency of chillers can have a considerable impact on total energy use, which would contribute to decarbonization. The centrifugal chiller and the screw chiller are the most widely used product in large-scale and medium-scale refrigeration applications, respectively, for the centrifugal compressor and screw compressor exhibit high efficiency within corresponding refrigerant flowrate ranges. At present, the commercial oil-free centrifugal chiller has achieved the ultra-high COP above 7.0 under the nominal water-cooled operating condition, by adopting two-stage compression with refrigerant injection into the inter-stage position, when the cooling capacity is higher than 3000 kW. However, the COP of the present water-cooled screw chiller reported is still lower than 6, and thus needed to be improved urgently.
