In: Mechanical Engineering
A pressurised air tank supplies compressed air to a new hybrid air engine. When the hybrid engine is not running the absolute pressure in the tank is 320 bar and the temperature of the air is 50°C.
Typical gas molecular values:
Gas Symbol Mr (g/mol)
Hydrogen H2 2
Oxygen O2 32
Carbon Dioxide CO2 44
Methane CH4 16
Nitrogen N2 28
Air (none available) 28.96
Calculate:
(a) The temperature of the air in the high pressure air tank when the air engine starts and the absolute pressure in the tank drops to 280 bar. Volume remains constant.
(b) The mass of air in the pressurised air tank using the temperature and pressure from part 1 (a) and the information given here below.
Note:1 m3 = 1000 litres
1 bar = 1 x 105 Pa
R is the universal gas constant and is always 8.314 J·K-1·mol-1
Tank volume = 450 litres pV = (m/Mr)RT