🔄 Supercritical CO2 Recompression Brayton

Size closed-loop supercritical CO2 (sCO2) recompression Brayton power loops: thermal efficiency (>45%), net electrical power (MW), split recompression ratio, and dual recuperator duties.

⚡ Fortran 90 Engine Double Precision (IEEE 754) ✓ ISO / ASME Validated

Thermodynamics

📊 Solver Telemetry ● ACTIVE

👁️ Views 38

⚡ Solves 33

💾 Downloads 452 📦 Fortran Code 11.4 KB

📅 Released Jun 2026

⏱️ Latency < 1 ms

⚛️ Closed-Loop sCO2 Recompression Power Cycle & Dual Recuperators

Real-time visual simulation: Dense-phase main compressor + bypass recompressor with LTR/HTR heat recovery

📝 Configuration & Presets

⚛️ Gen-IV Nuclear (650°C) ☀️ Solar Tower CSP (700°C) 🔥 Allam Oxy-Fuel (1100°C) 🏭 SMR Compact sCO2 (550°C)

⚡ Operating Pressures & Temperatures

High Pressure P_high [MPa]: 1 MPa = 10 bar

Low Pressure P_low [MPa]: Near critical point (7.38 MPa)

Turbine Inlet Temp TIT [°C]:

Main Comp. Inlet Temp [°C]:

⚙️ Mass Flow & Split Recompression

Total sCO2 Mass Flow ṁ [kg/s]:

Recompression Fraction γ (0.1 - 0.5): Fraction bypassing precooler to RC

Turbine Isentropic Eff. η_t:

Main Compressor Eff. η_MC:

sCO2 Recompression Brayton Formulation:
• Net Cycle Work: w_net = w_t − (1−γ)·w_MC − γ·w_RC [kJ/kg]
• Thermal Efficiency: η_th = w_net / q_heater [%]
• Dense-phase compression near critical point (ρ ≈ 600 kg/m³) drastically cuts pump work.
• Dual recuperators (LTR & HTR) eliminate pinch-point heat exchange mismatch.

📊 sCO2 Cycle Results

📊 Output Summary
💾 Fortran Source

Net Electrical Power Output (Ẇ_net)

51.06 MW

Thermal Efficiency: 35.64 % | Reactor Duty: 143.2 MW

P_high = 30 MPa (300 bar)

Gross Turbine Power (Ẇ_t) 63.53 MW η_t = 93 %

Main Compressor Power (MC) 6.06 MW Flow = 72 %

Recompressor Power (RC) 6.41 MW γ = 28 %

Precooler Heat Rejection 92.19 MW Low-temp heat sink

📈 Thermal Efficiency η (%) vs Recompression Fraction γ

📉 Net Power Output W_net (MW) vs Turbine Inlet Temp TIT (°C)

=================================================================
 THERMOFLUIDCALC — SUPERCRITICAL CO2 RECOMPRESSION BRAYTON REPORT
=================================================================
Case Title                 : Direct-Fired Oxy-Combustion Allam-Fetvedt Zero-Emission sCO2
Pressure Range             : P_high = 30.00 MPa (300.0 bar), P_low = 8.00 MPa (80.0 bar)
Temperatures & Mass Flow   : TIT = 1100.0 C, MC Inlet = 33.0 C, Total m_dot = 150.0 kg/s
Split Recompression Ratio  : gamma = 0.280 (RC flow = 42.0 kg/s, MC flow = 108.0 kg/s)
-----------------------------------------------------------------
NET ELECTRICAL POWER (Wnet): 51.057 MW (51056.6 kW)
CYCLE THERMAL EFFICIENCY   : 35.642 %
Gross Turbine Power Output : 63.526 MW
Main Compressor Power (MC) : 6.059 MW
Recompressor Power (RC)    : 6.410 MW
Main Heater / Reactor Duty : 143.250 MW
Precooler Heat Rejection   : 92.193 MW
=================================================================

📘 Calculation Methodology & sCO2 Brayton Standards

Near-Critical Compression Advantage

Compressing supercritical $CO_2$ just above its critical point ($31.1^\circ\text{C}, 7.38\,\text{MPa}$) exploits high density ($\sim 600\,\text{kg/m}^3$), reducing compressor power consumption by over $60\%$ compared to ideal gases.

Split-Flow Recompression Architecture

The recompression compressor (RC) takes a fraction $\gamma$ of hot low-pressure fluid directly from the LTR outlet without cooling, perfectly matching the specific heat capacitance rates ($mc_p$) across the recuperator.

Key Engineering Assumptions

Closed-loop closed Brayton cycle with pure $CO_2$.
Dual printed-circuit heat exchangers (PCHE) for LTR and HTR.
Applicable to Gen-IV nuclear reactors, solar tower CSP, and waste heat recovery.

ThermoFluidCalc Engineering Report