Develop two dynamic models of the process heat exchanger shown in Figures E17.2(a)(a) and E17.2(a)(b), one with the simple option and another with the rigorous option. In this process heat exchanger, at the design condition, Stream 1, a mixture of methane and ethane, is to be heated to 200°C by a hot stream of ethane. Initially the process is at steady state. Then the flowrate of Stream 1 is decreased by a step change to 45 kmol/h. Show the transient response of the outlet temperatures of the hot and cold streams from both the heat-exchanger models. Assume heat loss to the environment to be negligible.

Figures E17.2

Figure E17.2

Transcribed Image Text:

Cold Gas In 100 kmol/h 50°C P = 5 bar YCH4= = 0.8 YC₂H6 = 0.2 Hot Gas In 50 kmol/h 300°C P= 3 bar YC₂H6 = 1.0 E-1101A E-1101B (a) Cold Gas Out 200°C Hot Gas Out Th,out = ? Cold Gas In 100 kmol/h 50°C P = 5 bar YCH4 = 0.8 YC₂H6 = 0.2 Hot Gas In 50 kmol/h 300°C P = 3 bar YC₂H6 = 1.0 E-1101 (b) Hot Gas Out Th,out= ? Cold Gas Out 200°C