Drawing No. EH–PG–005 // Power Generation & Grid
Steam Power Cycle Simulator
Reviewed August 2026
Follow water and steam through a simplified power plant. Change the cycle conditions and watch mass flow, phase, boiler heat input, turbine output, condenser duty and cooling-water demand update directly on the plant drawing.
What does the simulator show?
The same mass of working fluid circulates continuously through the boiler, turbine, condenser and feed pump. The interactive drawing makes that closed mass loop visible while also showing where energy enters, leaves and becomes useful cycle work. A separate cooling-water loop removes the condenser heat.
Primary interactive view
Steam-water mass and energy flow
Animated paths show flow direction. Pipe labels report the current thermodynamic state; click a component for its local balance.
Plant controls
Plant balance
Secondary thermodynamic view
Temperature-entropy (T-s) diagram
Use this plot to connect the physical plant to the underlying thermodynamic states. The plant-flow drawing above remains the primary view; advanced Rankine configurations are intentionally left to the dedicated Rankine Cycle Simulator.
States 1 and 2 nearly coincide on this T-s scale; the compressed-liquid pump temperature change is not resolved by this saturation-table model.
Background
Condensate leaves the condenser as saturated liquid, the feed pump raises it to boiler pressure, the boiler adds heat until it becomes dry saturated steam, and the turbine expands that steam back to condenser pressure. The condenser then removes the remaining heat so the cycle can repeat. In steady state, the working-fluid mass flow is the same around the closed loop.
The condenser rejects a large amount of latent heat, while each kilogram of cooling water is normally allowed to warm by only a limited number of degrees. This simulator uses the sensible-heat balance ṁcw = Qcond /(cp ΔT), with cp = 4.18 kJ/kg·K. The resulting cooling-water flow can therefore be many times the steam flow.
The model uses a warm-end condenser terminal approach: Tcond = Tcw,out + approach. The corresponding saturation pressure is then interpolated from the steam table and becomes the turbine backpressure. Warmer cooling water therefore raises condensing temperature and pressure, reduces the turbine expansion ratio and normally reduces cycle power and efficiency. This is a simplified steady-state condenser model; a detailed design would solve heat-transfer area, overall U-value, fouling, non-condensables and cooling-water hydraulics together.
Saturation temperature, specific volume, enthalpy and entropy are interpolated from an embedded 47-point saturated steam table spanning 1 kPa to the critical point. Pressure-based property interpolation is linear in log pressure between tabulated saturation points. The feed pump is idealized with incompressible liquid work vΔP. The model intentionally omits superheat, reheat, regenerative heaters, pressure losses, generator losses, condenser subcooling and detailed cooling-system hydraulics. It is an educational process simulator, not a plant design model.
For engineering-grade water and steam properties, use the current IAPWS formulations rather than this coarse embedded table. The IAPWS-IF97 industrial formulation is the international steam-power-industry formulation, while NISTIR 5078 tabulates saturation and single-phase water/steam properties from IAPWS-95. The 10–12% turbine-exit moisture screening note is a teaching rule of thumb; actual permissible wetness depends on turbine design and operating limits.
Frequently asked questions
Practical questions about the steam-water and cooling-water loops.
Not in this steady-state model. Specific turbine work, pump work, heat input and efficiency are set by the thermodynamic states. Increasing steam flow scales the total turbine power, boiler duty, condenser duty and cooling-water requirement approximately in direct proportion.
Most of the turbine exhaust is still vapor and must release its latent heat of condensation. Cooling water, by contrast, normally experiences only a modest temperature rise. A large water mass flow is therefore required to carry away the condenser duty.
With the condenser terminal approach held constant, warmer cooling water requires a higher condensing temperature. Saturation pressure therefore rises, increasing turbine backpressure and reducing the available expansion work. The simulator now couples cooling-water temperature directly to condenser pressure so this effect appears in power, efficiency, moisture and heat-rejection results.
The T-s diagram connects the physical components to classical thermodynamics, but it is deliberately secondary on this page. The separate Rankine Cycle Simulator is the appropriate tool for superheat, reheat, regeneration, h-s plots and detailed state-point analysis.