Regenerative Multiphysics Framework for High-Density Energy Harvesting via Cryogenic Phase-Change and HTS-MHD Integration

AbstractThe Smart-Cryogenic HTS-MHD Hybrid Generator (SCG-HMH) is a hybrid power generation system that combines cryogenics, high-temperature superconductivity (HTS), and magnetohydrodynamics (MHD) to convert external excess heat energy into high-density electrical power with overall efficiencies of 50–70% when integrated with sufficient external heat sources.The system uses atmospheric nitrogen (N₂) as the working fluid in a semi-closed-loop configuration (>90% recirculation), exploiting the 1:694 volumetric expansion ratio of liquid nitrogen (LN₂) from its cryogenic state at -196°C to gaseous form, driving a high-speed radial turbo-expander. Frictionless operation is ensured by YBCO flux-pinned HTS magnetic bearings capable of sustaining up to 80,000 RPM. Energy harvest occurs in dual stages: superconducting induction for initial electrical conversion and MHD plasma interaction for high-density power extraction.The SCG-HMH is explicitly designed as an open system with respect to energy input. It continuously receives excess heat energy from external sources — such as industrial waste heat streams, geothermal sources, wind turbine waste heat, concentrated solar thermal, or other high- or mid-grade thermal inputs — which serve as the primary driver for high performance and net electrical output relative to electrical input alone. This openness ensures full compliance with the first and second laws of thermodynamics while enabling COP values >1 when substantial external heat is available.Key operational improvements include:

• LN₂ precooling of the cryo air compressor (10–15% compression work reduction)
• PSA/membrane purification (>99.9% N₂ purity, 5–10% preprocessing savings)
• Direct LN₂ cooling of auxiliaries (controls, pumps, AI systems) with heat recycling
• Ferrofluid self-repairing seals (<10⁻¹¹ cc/sec leaks, 1–2% LN₂ makeup reduction)
• Non-equilibrium MHD plasma (Te >> Tg, σ=10–50 S/m, α~20–50%) for 50–100 MW/m³ power density
• AI-controlled variable throttling (30–120% flow) for load matching and off-design loss minimization

Thermodynamic calculations and SymPy-based simulations confirm realistic performance when coupled with external heat supplies (100–500+ kW typical). COP ranges from 0.55–0.80 (stand-alone or low-heat) to 1.0–2.0+ (with substantial external heat). The system is positioned as a scalable solution for distributed generation, grid balancing, and waste-heat-to-power applications.

 

References and citation is the white paper