Overview
Engineering reference data for Critical Point Water Steam in thermodynamics.
Key Formulas
First Law
Energy is conserved — heat added minus work done.
Ideal Gas Law
Relates pressure, volume, and temperature of an ideal gas.
Heat Transfer
Sensible heat transfer.
Carnot Efficiency
Maximum efficiency between two temperatures.
Variables
| Symbol | Description | Unit |
|---|---|---|
| Internal energy | J | |
| Heat | J | |
| Work | J | |
| Pressure | Pa | |
| Volume | m³ | |
| Temperature | K |
Critical Point Properties
The critical point of water represents a state where the liquid and gas phases become indistinguishable, and no phase change occurs with pressure increase or heat addition.
- Pressure: 217.75 atm = 220.64 bar = 22.064 MPa = 3200.1 psi
- Temperature: 647.096 K = 373.946 °C = 705.103 °F
- Density: 0.322 g/cm³ = 0.6248 slug/ft³ = 20.102 lbm/ft³
Triple Point Properties
The triple point of water is the condition where solid (ice), liquid (water), and gas (steam) coexist in thermodynamic equilibrium.
- Pressure: 0.00604 atm = 6.12 mbar = 611.657 Pa = 0.08871 psi
- Temperature: 273.16 K = 0.01 °C = 32.02 °F
- Liquid Density: 0.99979 g/cm³ = 1.93991 slug/ft³ = 62.4148 lbm/ft³
Supercritical vs Superheated Steam
- Supercritical steam exists above the critical point, where water transitions directly to a supercritical fluid without boiling, exhibiting combined liquid and gas properties.
- Superheated steam is formed when saturated steam (at subcritical pressures) is heated above its saturation temperature, remaining in the gas phase with distinct phase boundaries.