LPG calculator

LPG composition

Select volume or mass percent composition

Volume fraction %vol

Ratio of propane or butane volume to the total volume of the mixture

Mass fraction %wt

Ratio of propane or butane mass to the total mass of the mixture

Description

q liq - volume flow rate of the liquid phase

LPG flow when it is in the liquid phase, before the evaporator

q gas - volume flow rate of the gas phase at normal conditions

LPG flow when it is in the gas phase, after the evaporator

V liq - velocity of the liquid phase

The velocity of LPG when it is in a liquid phase before it evaporates

V gas - velocity of the gas phase

The velocity of LPG when it is in the gas phase, after the evaporator

D liq - pipe diameter of the liquid phase

Internal pipe diameter of the LPG line liquid phase before the evaporator

D gas - pipe diameter of the gas phase

Internal pipe diameter of the LPG line gas phase after the evaporator

ṁ - mass flow rate

LPG flow rate in terms of mass flow in the unit of time. Conserved between liquid and gas phase of LPG

P - combustion heat power

Heat power generated after the combustion of LPG. Actual heat power should be reduced for the efficiency loses

LHV_G - lower heating value - mass

The heating value of LPG mixture - energy released during the combustion of a unit of mass

p - absolute pressure of LPG gas

The pressure of the LPG after the evaporator or after the pressure control valve

T - gas temperature

The temperature needed to calculate LPG density after the evaporator or after the pressure control valve

ρ gas - gas actual density

Calculated density for entered pressure and temperature, and mixture components ratio

ρ gas_nor - gas density at normal conditions

A density of LPG mixture at normal conditions p=101325 Pa and t=0⁰C

M -molar mass

Calculated molar mass for the selected ratio of propane and butane in the LPG mixture

Calculation setup

Select value to calculate. You should enter not selected one.

P

combustion heat power calculation

q liq/q gas/ṁ

LPG flow rate calculation

Select value to input. You should enter selected one. The other two will be calculated

ṁ

mass flow rate

q liq

liquid phase flow rate

q gas

gas phase flow rate

Select value to input. You should enter selected one. The other one will be calculated. Available only if the gas is selected fluid

V liq

liquid phase velocity

D liq

liquid phase pipeline diameter

Select value to input. You should enter selected one. The other one will be calculated. Available only if the gas is selected fluid

V gas

gas phase velocity

D gas

gas phase pipeline diameter

Why you should use this calculator?

The calculator can be used for estimation of flow rate, pipe diameter and heat power of liquefied petroleum gas - LPG. Liquefied petroleum gas is a mixture of propane, butane, and other components. As an example, you can use the calculator to determine the necessary flow rate of an LPG in a gas furnace, for required burner heat power.

How is the calculation executed?

The calculator is applicable for calculation of flow rate and heat power of gas and liquid phase of LPG. It can be used for calculation of clear propane or clear butane gas flow as well.

Propane and butane in a gas state are compressible. The calculator considers LPG as incompressible which is correct only for LPG liquid state. All physical properties, like mixture density or LPG component partial pressure, are calculated for the selected propane-butane mixture ratio.

The calculator can be used for computation of pipe diameter when the flow rate is known. The flow rate of LPG can be presented as mass flow rate, volume flow rate of the liquid phase or as a volume flow rate of the gas phase at standard conditions.

With the calculator, you can convert between mass and volume flow rate (liquid or gas phase). The calculator calculates a gas phase flow rate of LPG at normal conditions: pressure (atmospheric) p = 101325 Pa and temperature T=273.15 K

When is this calculator not relevant?

You can't use this calculator to calculate pressure drop through the pipe line. For that purpose please select pressure drop calculator for liquids or for gases.