Enter Phase Change Inputs
Use engineering property data for your selected material.
Example Data Table
This sample uses water-like properties at constant pressure.
| Mass (kg) | Initial Temp (°C) | Final Temp (°C) | Melting Point (°C) | Boiling Point (°C) | csolid | cliquid | cvapor | Lf | Lv | Expected Net Heat (kJ) |
|---|---|---|---|---|---|---|---|---|---|---|
| 2.0 | -20 | 130 | 0 | 100 | 2.10 | 4.18 | 2.00 | 334 | 2257 | 6222.000 |
Formula Used
This calculator treats the diagram as a constant-pressure heating or cooling curve. Total heat is the sum of sensible segments and latent plateaus.
Qsensible = m × c × ΔT
Qfusion = m × Lf
Qvaporization = m × Lv
Qtotal = ΣQsensible + ΣQlatent
Where:
- m = mass in kilograms
- c = specific heat for the active phase
- ΔT = temperature change inside one phase region
- Lf = latent heat of fusion
- Lv = latent heat of vaporization
When the temperature path crosses melting or boiling points, the calculator inserts a flat energy plateau. Heating gives positive heat transfer. Cooling gives negative heat transfer.
How to Use This Calculator
- Enter the material mass in kilograms.
- Provide starting and ending temperatures in Celsius.
- Enter melting and boiling points for your material.
- Input phase-specific heat capacities.
- Enter latent heats of fusion and vaporization.
- Click Generate Diagram Result.
- Review the total heat, segment table, and phase chart.
- Use the CSV or PDF buttons to export your result.
Frequently Asked Questions
1. What does this calculator estimate?
It estimates sensible heat, latent heat, total heat transfer, state transitions, and the plotted heating or cooling path across phase boundaries.
2. Why are some chart sections flat?
Flat sections represent latent heat plateaus. Energy changes there, but temperature stays constant during melting, freezing, boiling, or condensation.
3. Can it model cooling as well?
Yes. If the final temperature is lower, the calculator applies cooling logic and reports negative net heat transfer.
4. Which unit system does it use?
It uses kilograms, degrees Celsius, and kilojoules. Keep all inputs consistent with those units for correct results.
5. Does it include pressure effects?
No. It assumes one constant-pressure curve. Pressure-dependent saturation shifts require a more detailed thermodynamic property model.
6. Why is my total energy negative?
A negative value means heat leaves the material. That happens during cooling, condensation, or freezing processes.
7. Can I use materials other than water?
Yes. Enter the correct melting point, boiling point, specific heats, and latent heats for your chosen engineering material.
8. What happens if both temperatures match?
The calculator returns zero net heat transfer and shows an isothermal hold without segment changes.