Performance Evaluation of Low-Grade Waste Heat Recovery for Power Generation via Thermoelectric Generators System of Different Configurations

Abstract

Low-grade waste heat recovery (WHR) from steam turbines presents an opportunity to enhance energy efficiency and minimize losses in power plant. This study evaluates the perfromance of thermoelectric generator (TEG) configurations under varying steam parameters (mass flow rate, quality, temperature), to identify optimal configurations. A MATLAB- based numerical model integrating thermodynamics, heat transfer, and thermoelectric priniciples is devolped to simulate four TEG arrangements: 100 × 100, 50 × 200, 25 × 400, and 12 × 833 (longitudinal). Simulations span a wide range of steam conditions: flow rates (5–20 kg s⁻¹), qualities (0.05–0.97), and temperatures (100–160 °C). Results shows that the longitudinal 12 × 833 configuration delivers the highest power output 15.62 kW at 20 kg s⁻¹, x = 0.97, and 36.88 kW at 160 °C emphasizing temperature's critical role. System efficiency increases by 36% when temperature rises from 100 to 160 °C, while improving quality enhances by 8–12%. The heat utilization factor is highest at low steam qualities (x = 0.05), reaching 59.4% at 100 °C (5 kg s⁻¹), but drops significantly at higher flow rates. Findings highlight the potential of longitudinal TEG arrangements to maximize WHR through enhanced latent heat extraction and thermal gradient management.