An initially evacuated tank is to be filled with O2 gas from a supply line which contains O2 at 1000 kPa and 25oC. The tank volume is 0.25 m3, and the tank is to be filled until the pressure inside the tank is 900 kPa. Determine the amount of heat transfer required if the temperature of the O2 in the tank is to be 40oC.
State i: Inlet (Supply Line); State 1: Initial State; State 2: Final State
Given: O2; Ti = 25oC; Pi = 1000 kPa; V = 0.25 m3; P2 = 900 kPa; T2 = 40oC
Assume: P1 = 0; m1 = 0 (initially evacuated). Also, as no information is given and these terms are unlikely to be significant, W = 0, and kinetic and potential energy can be neglected. No flow out of the tank.
O2 is an ideal gas with variable specific heats.
What will be an ideal response?
Solution: With the assumptions given employed, the general First Law can be reduced to
Q + mihi = m2u2
From the conservation of mass, mi = m2
At Ti = 25oC, hi = 271.31 kJ/kg
At T2 = 40oC, u2 = 203.63 kJ/kg
From the ideal gas law, mi = m2 = P2V2/RT2 = 2.77 kg
where R = 0.2598 kJ/kg-K, and T = 313 K.
You might also like to view...
A drafter does only the menial chores around an office.
Answer the following statement true (T) or false (F)
____________________ principles are rules used to explain how people respond to what they see.
Fill in the blank(s) with the appropriate word(s).
When possible, the best indicator of the breeding merit of an animal is:
A. its performance in the desired traits. B. the performance of its progeny in the desired traits.
Technician A says that the Atkinson cycle improves combustion efficiency by leaving the intake valve open longer than normal. Technician B says that this increases the effective compression ratio. Which technician is correct?
A) Technician A only B) Technician B only C) Both technicians D) Neither technician