An air cycle refrigeration plant operates with a centrifugal compressor and an air turbine mounted coaxially such that the power output from the turbine contributes to the power required to drive the compressor. The temperature of the air at the compressor inlet is 15oC and the pressure ratio is 2.5. The air during its passage from the compressor to the turbine passes through an intercooler and enters the turbine at 40oC. The cold space temperature is required to be maintained at 15oC. Taking the isentropic efficiency of both compressor and turbine to be 84% and the mechanical efficiency of the turbine compressor drive as 90%, calculate the following: i. Refrigerating effect ii. Mass flow rate per kilowatt of refrigeration capacity iii. Driving power required per kilowatt of refrigeration capacity.