Ideal Flash Steam Fraction Calculator

How the ideal flash steam fraction calculator works

Ideal flash mass fraction = (initial liquid enthalpy − final saturated-liquid enthalpy) ÷ (final saturated-vapor enthalpy − final saturated-liquid enthalpy). Multiply by 100 for percentage, or by initial mass for ideal vapor mass. The remaining mass is initial mass minus flashed mass.

All enthalpies must use matching kJ/kg and one datum at reviewed states. Vapor enthalpy must exceed liquid enthalpy, and initial enthalpy must lie between those final saturation values for this two-phase fraction model. Out-of-domain values are rejected rather than clamped. No pressure-property lookup or safe depressurization/equipment advice is provided.

Quantities use the stated units and finite bounded inputs. Whole purchases round up under the documented model; cost components round half-up to cents before totals are summed. Undefined ratios stay unavailable. π and logarithms use normal numeric precision. Display rounding does not alter the entered assumptions.

Worked example

An initial 500 kJ/kg and final saturation values of 400 and 2,400 give (500−400)/(2,400−400) = 5%. From 1,000 kg this is 50 kg ideal vapor. Raising initial enthalpy to 600 kJ/kg gives 10% and 100 kg.

Sources and assumptions

The source material explains the underlying calculation or pricing structure. Entered prices, costs, schedules and scenario choices are your assumptions; this tool does not obtain supplier quotes or predict actual results.

• Spirax Sarco flash steam