Agas refrigeration cycle with a pressure ratio of 4 uses helium as the working fluid. the temperature of the helium is -3°c at the compressor inlet and 54'c at the turbine inlet. assume isentropic efficiencies of 88 percent for both the turbine and the compressor (given: the properties of helium are cp=5.1926 kj/kg k and k = 1.667.) determine the mass flow rate of the helium for a refrigeration rate of 30 kw. the mass flow rate of the hellum is kg/s? ?