ME354 Thermodynamics 2

Problem Set #8: Non-Reacting Mixtures

Problem 8: 10-10

A mixture of 40 percent argon and 60 percent hydrogen by volume has been proposed for use as the working fluid in a closed Brayton cycle. The mixture is compressed isentropically from 40 oC at 0.4 x 106 N/m2 to a pressure of 1.2 x 106 N/m2. Find the final temperature of the mixture and the work required, assuming perfect-gas behavior is applicable.

Answer: T₂ = 447 K, W = 199.9 kJ/kg

Solution

(67.2 KBytes)

Problem 8: 10-13

One tank contains 2 kg of methane at 2 atm, 10 oC. Another tank contains 4 kg of oxygen at 6 atm, -10 oC. A valve between the tanks is opened, and the gases mix adiabatically. Find the final mixture temperature and pressure.

Answer: T_f = 274.5 K, P = 2.96 atm

Solution

(68.4 KBytes)

Problem 8: 10-41

Atmospheric air at 90 oF and 50 percent relative humidity is to be conditioned to 70 oF at 35 percent relative humidity using a cooling coil section, a condensate removal section, and a reheat section. The air-flow is 350 lbm/hr. At 1 atm find the mass of water removed and the heat transfers.

Answer: m_H2O = 3.38 lbm/hr, Q_cool = 7910 Btu/hr, Q_heat = 2485 Btu/hr,

Solution

(92.7 KBytes)

Problem 8: 10-61

A cooling water tower is used to cool water from 100 oF to 75 oF at a water-flow rate of 200,000 lbm/hr. The air enters the bottom of the tower at 60 oF with a relative humidity of 50 percent and leaves the top at 90 oF, saturated. Find the air-flow rate and the makeup water required.

Answer: m_a = 142286 lbm/hr, m_mu = 3557 lbm/hr

Solution

(64.4 KBytes)

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