 # Steam Turbine Calculator watch tutorialview guide

Solve for:

### Inlet Steam

Pressure* psig
* °C btu/lbm kJ/kg/K

### Turbine Properties

Selected Turbine Property
Mass Flow * klb/hr
Isentropic Efficiency * %
Generator Efficiency * %
Power Out * kW

### Outlet Steam

Pressure* psig
* °C btu/lbm kJ/kg/K
* Required [reset]
Allowed Range / Limits
Minimum
Maximum
**Example: Solve for Isentropic Efficiency

 Examples: Mouse Over Solve for Outlet Properties Solve for Isentropic Efficiency

## Inlet Steam

Mass Flow84.3 klb/hr
Pressure427.8 psig Sp. Enthalpy1,329.1 btu/lbm
Temperature340.1 °C Sp. Entropy6.698 kJ/kg/K
PhaseGas Energy Flow118,210     ## Outlet Steam

Mass Flow84.3 klb/hr
Pressure156.2 psig Sp. Enthalpy1,243.4 btu/lbm
Temperature230.7 °C Sp. Entropy6.755 kJ/kg/K
PhaseGas Energy Flow110,589
Isentropic Efficiency 87.6 % 7,621 92.9 % 1,966.7 kW

## Calculation Details

### Step 1: Determine Inlet Properties

Using the Steam Property Calculator, properties are determined using Inlet Pressure and the selected second parameter (Temperature, Specific Enthalpy, Specific Entropy, or Quality). The Specific Enthalpy is then multiplied by the Mass Flow to get the Energy Flow:
• Inlet Energy Flow = Specific Enthalpy * Mass Flow
[ Inlet Energy Flow = 118,210 = 1,329.1 btu/lbm * 84.3 klb/hr ]

### Step 3: If solve for 'Isentropic Efficiency', Determine Outlet Properties

Using the outlet specific enthalpy, calculate the isentropic efficiency:
• Isentropic Efficiency = (Inlet Specific Enthalpy - Outlet Specific Enthalpy) / (Inlet Specific Enthalpy - IDEAL Outlet Specific Enthalpy)
[Isentropic Efficiency = 87.57 % = (1,329.1 btu/lbm - 1,243.4 btu/lbm) / (1,329.1 btu/lbm - 1,231.2 btu/lbm)]

### Step 3: If solve for 'Outlet Properties', Determine Outlet Specific Enthalpy

1. Isentropic Efficiency = (Inlet Specific Enthalpy - Outlet Specific Enthalpy) / (Inlet Specific Enthalpy - IDEAL Outlet Specific Enthalpy)
2. Isentropic Efficiency * (Inlet Specific Enthalpy - IDEAL Outlet Specific Enthalpy) = (Inlet Specific Enthalpy - Outlet Specific Enthalpy)
3. Outlet Specific Enthalpy = Inlet Specific Enthalpy - Isentropic Efficiency * (Inlet Specific Enthalpy - IDEAL Outlet Specific Enthalpy)
Using the outlet specific enthalpy, calculate the outlet properties:

### Step 4: Calculate Steam Turbine Energy Out and Generation (Power Out)

• Energy Out = (Inlet Specific Enthalpy - Outlet Specific Enthalpy) * Mass Flow
[Energy Out = 7,621 = (1,329.1 btu/lbm - 1,243.4 btu/lbm) * 84.3 klb/hr]
• Power Out = Energy Out * Generator Efficiency
[Power Out = 1,966.7 kW = 7,621 * 92.90 %]

## Assumptions

• Inlet Mass Flows equal Outlet Mass Flow.