A two-step, steady-state process is used to compress 100 kg/min of nitrogen from P = 1 bar and T = 250 K to P = 10 bar and T = 250 K. First, an adiabatic compressor is used to convert the nitrogen from P = 1 bar and T = 250 K to P = 10 bar and T = 300 K. Then a heat exchanger is used to cool the nitrogen to T= 250 K. Find the work added in the compressor, and the heat removed in the heat exchanger.

A. Use an ideal gas model.

B. Use Figure 2-3 as much as possible. If you need an equation of state, use the van der Waals equation, with a = 1.37 × 10⁶ bar · cm⁶/mol² and b = 38.6 cm³/mol.

Transcribed Image Text:

THERMODYNAMIC PROPERTIES OF NITROGEN 0 250 A kJ/kg FIGURE 2-3 Thermodynamic diagram for nitrogen. 50 100 000 150 200 300 007 350 400 50-0.3 m²/kgl 450 20 10 8 6 4 2 P, MPa 1 0.8 0.6 0.4 -0.2 0.1 500 Based on WC. Reynolds, Thermodynamic Properties in SI, Department of Mechanical Engineering, u 5L51 Mini S