Cascade refrigeration is used in systems that require cooling over large temperature ranges. This can achieved using interstage cooling as configured in Figure 5.10 of Elliot and Lira, 2nd edition, (see figure and read the section). In this problem, we have a system with such configuration using refrigerant R-134a and saturated liquid leaving the condenser at 40C. The pressure of the flash chamber and the intermediate pressure between compressors is to be 0.290MPa. The evaporator operates at 20C where the outlet is saturated vapor. The flowrate of stream 1 in Figure 5.10 of Elliot and Lira is 23kg/h. The flash chamber may be considered adiabatic. The compressors may be considered to be reversible for the purposes of this problem. (a) Find a PH diagram for this system and plot this cycle on it. (b) Calculate the work input required to the first compressor in kJ/h. (c) Calculate the flowrates of streams 7 and 6. (d) Calculate the enthalpy of stream 4. Cascade refrigeration is used in systems that require cooling over large temperature ranges. This can achieved using interstage cooling as configured in Figure 5.10 of Elliot and Lira, 2nd edition, (see figure and read the section). In this problem, we have a system with such configuration using refrigerant R-134a and saturated liquid leaving the condenser at 40C. The pressure of the flash chamber and the intermediate pressure between compressors is to be 0.290MPa. The evaporator operates at 20C where the outlet is saturated vapor. The flowrate of stream 1 in Figure 5.10 of Elliot and Lira is 23kg/h. The flash chamber may be considered adiabatic. The compressors may be considered to be reversible for the purposes of this problem. (a) Find a PH diagram for this system and plot this cycle on it. (b) Calculate the work input required to the first compressor in kJ/h. (c) Calculate the flowrates of streams 7 and 6. (d) Calculate the enthalpy of stream 4