Equivalent Evaporation
'From-and-at 100 °C' evaporation - the canonical boiler capacity rating. m_eq = m·(h_g − h_fw)/2257.
Equivalent evaporation
26,141kg/h
Multiplier
1.046×
Formula, assumptions, and limits
The 2257 kJ/kg denominator is h_fg at 100 °C atmospheric. Equivalent evaporation lets boilers with different operating pressures and feedwater temperatures be compared on one rating number.
Symbol legend
| Symbol | Meaning | Unit | Source |
|---|---|---|---|
| Actual steam produced | kg/h | steam meter | |
| Enthalpy at outlet | kJ/kg | steam tables at P, superheat T | |
| Feedwater enthalpy entering boiler | kJ/kg | feedwater tank T | |
| h_fg at 100 °C | kJ/kg | IAPWS-IF97 constant |