Method
Water sensible-heat duty divided by supplied heater efficiency.
Equations
ΔT = t2 − t1
Q = ṁ · cp · ΔT
P = Qη
Symbols and units
| Symbol | Quantity | Unit |
|---|---|---|
| Inputs | ||
| ṁ | Water mass flow | kg/s |
| cp | Water specific heat | kJ/kg·K |
| t1 | Inlet temperature | °C |
| t2 | Outlet temperature | °C |
| η | Heater efficiency | 0–1 |
| Results | ||
| ΔT | Temperature rise | K |
| Q | Water heat duty | kW |
| P | Heater input | kW |
Assumptions and limits
- Specific heat and efficiency are explicit inputs.
Worked example
The input values are the calculator's own verification test, run through the calculator. They show the working; they are not design values.
Inputs
| ṁ | Water mass flow | 0.1 kg/s |
| cp | Water specific heat | 4.186 kJ/kg·K |
| t1 | Inlet temperature | 20 °C |
| t2 | Outlet temperature | 60 °C |
| η | Heater efficiency | 0.9 0–1 |
Results
| ΔT | Temperature rise | 40 K |
| Q | Water heat duty | 16.744 kW |
| P | Heater input | 18.6044 kW |
A preliminary check for engineer review, not an engineering approval. The project calculation to the applicable codes, authority requirements and specification governs.