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Sigma Programmable Object - What formula is used to calculate Enthalpy?

Issue

How is Enthalpy calculated in Sigma?

Environment

Programmable Object

Prog Point

Enthalpy

Cause

Customers request for this information.

Resolution

A Programmable Object calculates Enthalpy using the following formula.


I = 1.006 * t + x * (2501 + 1.8 * t) where

t is the temperature and  

x = 0.62198 * (í * pdm / (p - í * pdm)) and at p = 101.325 kPa =>

x = 0.62198 * (í * pdm / (101.325 - í * pdm))    


where   í is relative humidity and    

pdm = p` = 101325 * 10A   where  


A = A0 - A1/T - A2*logT - A3*10(-T/A4) + A5*10(A6/T)   where


A0 = 20.82648355  

A1 = 2948.997118  

A2 = 5.02808  

A3 = 29811.33781  

A4 = 32.923061  

A5 = 25.21934913  

A6 = 1302.8503  


T = absolute temperature = 273.15 + t

 

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Last update:
‎2018-09-06 12:07 PM
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