The Brayton refrigeration cycle is modified by the introduction of a regenerative heat exchanger. In the modified cycle, compressed air enters the regenerative heat exchanger at 350 K and is cooled to 320 K before entering the turbine. Determine, for the modified cycle,
(a) the lowest temperature, in K.
(b) the net work input per unit mass of air flow, in kJ/kg.
(c) the refrigeration capacity, per unit mass of air flow, in kJ/kg.
(d) the coefficient of performance.