Q1 : A cascade refrigeration system is designed to supply 10tonnes of refrigeration at an evaporator temperature of -40°C and acondenser temperature of 36°C. The load at -40°C is absorbed by aunit using R-22 as the refrigerant and is rejected to a cascadecondenser at -10°C. The cascade condenser is cooled by a unit usingR-12 as the refrigerant and operating between - 20°C evaporatingtemperature and 36°C condenser temperature. The refrigerant leavingthe R-22 condenser is subcooled by 5°C but there is no subcoolingof R-12 refrigerant. The gas leaving both the evaporators is dryand saturated and the compressions are isentropic. Neglectinglosses. the enthalpy of refrigerant at lower evaporator exit is : *A--154.89 [kJ/kg] B-334.18 [kJ/kg] C-388.13 [kJ/kg] D-163.86[kJ/kg] -----------------------------------------------Q2 : Acascade refrigeration system is designed to supply 10 tonnes ofrefrigeration at an evaporator temperature of -40°C and a condensertemperature of 36°C. The load at -40°C is absorbed by a unit usingR-22 as the refrigerant and is rejected to a cascade condenser at-10°C. The cascade condenser is cooled by a unit using R-12 as therefrigerant and operating between - 20°C evaporating temperatureand 36°C condenser temperature. The refrigerant leaving the R-22condenser is subcooled by 6°C but there is no subcooling of R-12refrigerant. The gas leaving both the evaporators is dry andsaturated and the compressions are isentropic. Neglecting losses.calculate the COP of whole system