What Is the Rankine Cycle Thermal Efficiency Calculator?
The Rankine cycle is a closed-loop thermodynamic cycle converting heat into mechanical shaft work using phase change of water/steam.
How Does the Rankine Cycle Thermal Efficiency Calculator Work?
Liquid water is pumped into a boiler, vaporized into high-pressure steam, expanded across a turbine to drive a generator, and condensed back into liquid.
Rankine Cycle Thermal Efficiency Calculator Formula & Variables
The core mathematical equation utilized by this calculator is expressed as:
Thermal efficiency is net work (turbine work minus feed pump work) divided by boiler heat input.
How to Use the Rankine Cycle Thermal Efficiency Calculator
- Enter steam enthalpy at the turbine inlet h₁.
- Specify turbine exhaust enthalpy h₂.
- Input condenser exit liquid enthalpy h₃.
- Provide boiler feedwater inlet enthalpy h₄.
Step-by-Step Example Calculation
Superheated Steam Power Plant
Input Values:
turbineInletEnthalpyH1:3410.0
turbineExitEnthalpyH2:2180.0
condenserExitEnthalpyH3:192.0
boilerInletEnthalpyH4:198.0
Worked Steps: Expanding steam from 3410 to 2180 kJ/kg generates 1224 kJ/kg of net work with 38.11% thermal efficiency and a heat rate of 8953 Btu/kWh.
Understanding Your Result
Thermal Efficiency: Percentage of input heat converted into net work.
Net Work Output: Usable electrical generation energy in kJ/kg.
Heat Rate: Fuel heat required per kilowatt-hour generated (Btu/kWh).
Factors That Affect the Result
- Boiler steam pressure and superheat temperature, and condenser vacuum temperature.
When Should You Use This Calculator?
- Coal, natural gas combined cycle, nuclear reactor, and concentrated solar thermal power plant design.
Assumptions & Limitations
- Assumes steady-state flow and isentropic turbomachinery without parasitic reheat losses.
Frequently Asked Questions
Why is the back-work ratio of a Rankine steam cycle so much smaller than a Brayton gas turbine?+
Because the working fluid is compressed as an incompressible liquid in the Rankine cycle, pump work consumes only 0.5%–1% of turbine output, compared to 40%–50% compressor work in gas turbines.
Calculation Accuracy & Reference Note
Standard ASME / IAPWS thermodynamic formulation.