Contents - Index


LowerHeatingValue

 

LowerHeatingValue [kJ/kg, kJ/kmol, J/kg, J/kmol, Btu/lbm Btu/lbmol] returns the specific lower heating value  of the specified substance at a reference temperature of 25C (77F).  The units of the value returned by this function depend on the user settings of the unit system. This function is implemented for ideal gases, the NASA gases (that contain only carbon, hydrogen, and oxygen) and organic incompressible fluids.

 

The LowerHeatingValue function requires only one argument and that is the name of the substance.  The function is not applicable for real fluids or brines.

 

The value of the lower heating value depends on the phase of the fuel.  The value returned by this function assumes that that the phase is what it would be at the reference temperature and standard atmospheric pressure.  Any water formed in the combustion process is assumed to be in the vapor state.

 

Examples:

 

$UnitSystem SI kJ molar

LHV_CH4=LowerHeatingValue(CH4)  {lower heating value of gaseous methane}

LHV_C2H5OH=LowerHeatingValue(C2H5OH) {lower heating value of liquid ethanol}

LHV_propanol=LowerHeatingValue('n-Propanol') {lower heating value of n-propanol (Incompressible fluid library)}

LHV_isooctane=LowerHeatingValue(C8H18,isooctane) {lower heating value for isooctane in the NASA library}

 

{Solution

LHV_C2H5OH=1.235E+06 [kJ/kmol]

LHV_CH4=802663 [kJ/kmol]

LHV_propanol=1.845E+06 [kJ/kmol]

LHV_isooctane=5.100E+06 [kJ/kmol]

}

 

Thermophysical Property Functions

HigherHeatingValue