# Material Content Section - Energy

Navigation: Models ➔ Common Sections ➔ Material Content Section ➔ Energy, Values at User T and P

Material (Content) Content Tab Include Properties Species (Sp) Optional Tabs
Basic Information Energy
ValuesAtUserTandP
Density Correction
Solubility
Saturation
Acidity
Charge
Transport
HeatsOfCombustion
Heating Values
Solution Impurity
H2O Properties
Water Quality Sp Tab
EC Tab
DLockup
LockUp
DTrack
Track
DSz
Sz
MSz
DSSA
SSA

## Introduction

These properties are related to the energy contained in the surge unit, e.g. specific heat, enthalpy, etc. These will only be shown if the user has chosen to display the Energy (Thermodynamic) Properties on the Plant Model - Views tab page.

## Data Sections

Tag (Long/Short) Input / Calc Description/Calculated Variables / Options

### Energy

These properties will only be shown if the user has chosen to display the Energy (Thermodynamic) Properties on the Plant Model - Views tab page or from the Include Properties dropdown list on the first page of the material Content section.

Specific Heat
Cp@0 Calc Cp of the total mixture in the content @ 0 °C.
Cp / Cp@T Calc Cp of the total mixture in the content @ temperature.
SmsCp@T Calc Solids Cp at the content temperature
LmsCp@T Calc Liquid Cp at the content temperature
VmsCp@T Calc Vapour Cp at the content temperature
SLmsCp@T Calc Slurry Cp at the content temperature
CpCv Calc The ratio of specific heat at constant pressure to specific heat at constant volume at the content temperature.
Enthalpy - Sensible
Hs@T Calc The change in enthalpy, dH, (excluding phase change) from 0°C to content temperature for the total mixture.
SmsHs@T Calc The change in enthalpy, dH, (excluding phase change) from 0°C to content temperature for the solids.
LmsHs@T Calc The change in enthalpy, dH, (excluding phase change) from 0°C to content temperature for the Liquids.
VmsHs@T Calc The change in enthalpy, dH, (excluding phase change) from 0°C to content temperature for the vapours, or gases.
SLmsHs@T Calc The change in enthalpy, dH, (excluding phase change) from 0°C to content temperature for the combined solids and liquids.
totHs Calc The total Hs at content temperature (Hs@T x mass flowrate).
Enthalpy - including Phase Change (Please see What is the difference between Hs and Hz?
Hz@T Calc The change in enthalpy, dH,(including phase change) from 0°C to content temperature for the total mixture.
totHz Calc The total Hz at content temperature (Hz@T x mass flowrate).
Total Enthalpy (previously called Enthalpy of Formation) Total Enthalpy = Heat of Formation at 25 + $\int\limits_{25}^{T}Cp dT\,$
Hf@0 Calc Total Enthalpy for the mixture at 0°C and 101.325 kPa, per mass.
Hf@T Calc Total Enthalpy for the mixture at the content temperature and pressure, per mass.
totHf@0 Calc Total Enthalpy @ 0°C and 101.325 kPa x mass flowrate
totHf@T Calc Total Enthalpy @ content temperature and pressure x mass flowrate
Entropy and Free Energy
S@0 Calc Entropy for the total mixture at 0°C and 101.325 kPa.
S@T Calc Entropy for the total mixture at the content temperature and pressure.
G@0 Calc Gibbs Free Energy (mass basis) for the total mixture at 0°C and 101.325 kPa. This is only visible in Build 138 and later.
G@T Calc Gibbs Free Energy (mass basis) for the total mixture at the content temperature and pressure. This is only visible in Build 138 and later.
mlG@T Calc Gibbs Free Energy (mole basis) for the total mixture at the content temperature and pressure. This is only visible in Build 138 and later.

### Values at User Defined T and P

If the ValuesAtUserTandP option is selected in the Plant Model - Species tab page or from the Include Properties dropdown list on the first page of the material Content section, then the following fields will also be shown:

UsrDefT Input User defined Temperature
UsrDefP Input User defined pressure. This will be the saturation pressure at the user defined temperature if * is entered for this field.
Density@U / Rho@U Calc Density of the total mixture at user defined temperature and pressure.
LiquidDensity@U / LRho@U Calc Density of the liquid phase at user defined temperature and pressure.
VapourDensity@U / VRho@U Calc Density of the vapour phase at user defined temperature and pressure.
SolidConc@U Calc The solids concentration at user defined temperature and pressure.
Cp@U Calc Heat capacity of the total mixture at user defined temperature and pressure.