Enthalpy Calculator Steam

Steam Enthalpy Equation:

\[ H = H_f + x \times H_{fg} \]

Liquid Enthalpy (H_f):

kJ/kg

Dryness Fraction (x):

dimensionless

Vaporization Enthalpy (H_fg):

kJ/kg

Total Enthalpy (H):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Steam Enthalpy?

Steam enthalpy is the total heat content of steam, consisting of the sensible heat of liquid water (H_f) plus the latent heat of vaporization (H_fg) multiplied by the dryness fraction (x). It's a crucial parameter in thermodynamics and heat transfer calculations.

2. How Does the Calculator Work?

The calculator uses the steam enthalpy equation:

\[ H = H_f + x \times H_{fg} \]

Where:

\( H \) — Total enthalpy (kJ/kg)
\( H_f \) — Liquid enthalpy (kJ/kg)
\( x \) — Dryness fraction (dimensionless, 0-1)
\( H_{fg} \) — Vaporization enthalpy (kJ/kg)

Explanation: The equation accounts for both the sensible heat of the liquid phase and the latent heat required for vaporization, weighted by the dryness fraction which represents the steam quality.

3. Importance of Enthalpy Calculation

Details: Accurate enthalpy calculation is essential for designing and analyzing steam systems, power plants, heat exchangers, and other thermodynamic processes. It helps determine energy content, work potential, and heat transfer requirements.

4. Using the Calculator

Tips: Enter liquid enthalpy (H_f) and vaporization enthalpy (H_fg) in kJ/kg, and dryness fraction (x) between 0 (saturated liquid) and 1 (saturated vapor). All values must be valid (enthalpies ≥ 0, 0 ≤ x ≤ 1).

5. Frequently Asked Questions (FAQ)

Q1: What is dryness fraction?
A: Dryness fraction (x) represents the mass fraction of vapor in a liquid-vapor mixture. x=0 means all liquid, x=1 means all vapor, and 0<x<1 means wet steam.

Q2: Where can I find H_f and H_fg values?
A: These values are typically found in steam tables corresponding to specific pressure and temperature conditions.

Q3: Can this be used for superheated steam?
A: No, this equation is for saturated steam. Superheated steam requires additional calculations accounting for the temperature above saturation.

Q4: What are typical H_fg values?
A: At atmospheric pressure (100°C), H_fg ≈ 2257 kJ/kg. The value decreases with increasing pressure.

Q5: Why is enthalpy important in engineering?
A: Enthalpy is fundamental for energy balance calculations, efficiency determinations, and system design in thermal and mechanical engineering applications.