Question

a. At pressure p=10 MPa, the Enthalpy (with reference to the tables A4/A5/A6/A7) for a closed system containing water is equal to 3000 kJ/kg.. What is the phase of the system?   ……………………………………….(1 point)
b. What is the Entropy for super heater vapor at p=10 MPa, and T=480℃? ………………………. (1 point)
c. Given below is missing data for air modeled as an ideal gas. Assuming constant Cp and Cv with temperature, fill out the table (3 points). k=1.4

Δs (kJ/(kg.K)) T_1 (K) T_2 (K) p_1 (bar) p_2 (bar)
600 1000 5 10
0 500 600 5
0  500 6 10
d. For a power cycle, Qin is 3000 kJ/kg, Qout is 1800 kJ/kg. The temperature of the cold reservoir is at 27℃. The temperature of the hot reservoir is 450℃. Determine if the Cycle is possible/feasible?
……………….. (1 point) Why…………………………………………………………………………? (1 point)

c. Air is leaking from a cylinder in a lab. Determine if this is steady state or transient state. Assuming the cylinder is well insulated, write the energy conservation equation for this system in terms of u_f, u_i, h_(air,out), m_i, m_f (3 points)

Answer 1