?An expander operates adiabatically with nitrogen entering at \(T_{1}\) and \(P_{1}\)

Chapter 7, Problem 7.27

(choose chapter or problem)

An expander operates adiabatically with nitrogen entering at \(T_{1}\) and \(P_{1}\) with a molar flow rate \(\dot n\). The exhaust pressure is \(P_{2}\), and the expander efficiency is η. Estimate the power output of the expander and the temperature of the exhaust stream for one of the following sets of operating conditions.

(a) \(T_{1} = 480°C, \quad P_{1} = 6 bar, \quad \dot n = 200 mol \cdot s^{−1}, \quad P_{2} = 1 bar, \quad η = 0.80\).

(b) \(T_{1} = 400°C, \quad P_{1} = 5 bar, \quad \dot n = 150 mol \cdot s^{−1}, \quad P_{2} = 1 bar, \quad η = 0.75\).

(c) \(T_{1} = 500°C, \quad P_{1} = 7 bar, \quad \dot n = 175 mol \cdot s^{−1}, \quad P_{2} = 1 bar, \quad η = 0.78\).

(d) \(T_{1} = 450°C, \quad P_{1} = 8 bar, \quad \dot n = 100 mol \cdot s^{−1}, \quad P^{2} = 2 bar, \quad η = 0.85\).

(e) T_{1} = 900(°F), \quad P_{1} = 95(psia), \quad \dot n = 0.5(lb mol)(s)^{−1}, \quad P_{2} = 15(psia), \quad η = 0.80\).

Text Transcription:

T_1

P_1

dot n

P_2

T_1 = 480°C, P_1 = 6 bar, dot n = 200 mol cdot s^−1, P_2 = 1 bar, η = 0.80

T_1 = 400°C, P_1 = 5 bar, dot n  = 150 mol cdot s^−1, P_2 = 1 bar, η = 0.75

T_1 = 500°C, P_1 = 7 bar, dot n  = 175 mol cdot s^−1, P_2 = 1 bar, η = 0.78

T_1 = 450°C, P_1 = 8 bar, dot n  = 100 mol cdot s^−1, P_2 = 2 bar, η = 0.85

T_1 = 900(°F), P_1 = 95(psia), dot n  = 0.5(lb mol)(s)^−1, P_2 = 15(psia), η = 0.80