How to Calculate the Size of a Propane Cloud Escaping from a Cargo Tank?

Depressurization Process

When propane steam is stored in a cargo tank at a certain pressure and escapes through a hole in a pipe, the process that occurs is known as depressurization. During depressurization, the pressure inside the tank decreases until it reaches atmospheric pressure. This results in the expansion of the propane to fill the volume of the container and form a cloud of gas.

Equation for Depressurization

The equation used to calculate the volume of gas during depressurization is given by:
v1p1^k = v2p2^k
Where:
v1 = volume of gas at absolute pressure p1
v2 = volume of gas at absolute pressure p2
k = ratio of specific heat (Cp/Cv = 1.15 for propane)
p1 = initial pressure (400 kPa)
p2 = final pressure (100 kPa)

Calculation of Propane Cloud Size

To calculate the size of the propane cloud escaping from the cargo tank, we can use the depressurization equation. By substituting the given values of v1, p1, p2, and k into the equation, we can determine the volume of the propane cloud formed.

Therefore, the size of the propane cloud will be approximately 1329.85 m³ if it does not mix with the air.