Getting Started Guide
Naming Conventions
Cp | Isobaric Heat Capacity | H | Enthalpy | Q | Duty / Power |
Cv | Isochoric Heat Capacity | S | Entropy | V | Volume |
U | Viscosity | T | Temperature | X | Quality (Vapor Fraction) |
K | Thermal Conductivity | P | Pressure | M | Mass/Mole Flow |
c | Component (Pure Fluid) | m | Mixture (Composition) |
Thermodynamic and transport functions are named using the following strategy:
H | P | T |
Output | Input 1 | Input 2 |
such as HPT
calculates enthalpy (H), given pressure (P) and temperature (T) for Water/Steam using IAPWS IF-97, or:
H | c | P | T |
Output | Component | Input 1 | Input 2 |
H | m | P | T |
Output | Mixture | Input 1 | Input 2 |
HcPT
calculates enthalpy given a component (fluid) name, pressure, and temperature, using REFPROP. Equally, HmPT
calculates enthalpy given a mixture (from a mixture sheet), pressure and temperature.
IAPWS-97 vs REFPROP
JSteam contains two thermodynamic packages depending on type of function call used.
IAPWS-97
If you only want to compute thermodynamic or transport properties of water or steam, and favour computational speed over accuracy (which for virtually all industrial cases is perfectly adequate, the accuracy is still really good), then JSteam uses the IAPWS 1997 Industrial Formulation. This is automatically used when the user calls a function without a component or mixture specified (i.e. it defaults to water). For example: HPT(1,100)
computes the Enthalpy of Water/Steam at 1 bar, 100 C (unit set dependent).
REFPROP
If you want to compute properties of any other fluid (or mixture) supported by JSteam, or if you want high accuracy water/steam computations, then JSteam utilizes REFPROP. This is the reference database for high accuracy thermodynamic and transport property computations, and is automatically used when the user calls a function with a component or mixture specified. For example: HcPT("methane",1,100)
computes the Enthalpy of Methane at 1 bar, 100 C (unit set dependent).
Essential Reading
- Workbook Setup
- A brief guide on how to setup an Excel workbook for use with JSteam.
- JSteam Ribbon
- Details the functionality of the JSteam Ribbon, and how to best utilize it.
- Inserting Functions
- Details the various methods to insert JSteam functions into your Excel workbook.
- Creating Mixtures
- How to create mixtures of elements and compounds for thermodynamic and combustion calculations.
- Estimating Variables
- Details the "Estimate" function and where it is useful.