A two-stage refrigeration system shown in Figure P11.60 operates on Freon-12 and has a cooling capacity of 50 kW, when the evaporator temperature is −40°C, while that of the condenser is 40°C. The...

A two-stage refrigeration system shown in Figure P11.60 operates on Freon-12 and has a cooling capacity of 50 kW, when the evaporator temperature is −40°C, while that of the condenser is 40°C. The system uses an intercooler where the lower-pressure condenser (points 2–3) is cooled by the evaporator of  high-pressure cycle (points 8–5). The intercooler temperature is 0°C. The Freon at points 1 and 5 is dry saturated vapor, while at points 3 and 7 it is a saturated liquid. The isentropic effi ciencies of the compressors are εc = 0.85. a. Draw the cycle on a T–s and p–h diagram. b. Find the power of the two compressors. c. Find the COP of the cycle. d. Find the COP of an equivalent cycle with a single compressor.