Thermodynamic and parametric analyses of a thermoelectric generator in a liquid air energy storage system

A thermoelectric generator was applied to the liquid air energy storage system to utilize the excess heat, whereas their coupled thermodynamic characteristics were rarely reported. This article conducted the thermodynamic and parametric analyses on system performance in detail. The effects of the hot water mass flow and outlet temperature of thermoelectric generator, the discharging pressure, and stages of expansion on the performance were investigated. The results showed that the hot water outlet temperature had significant impact on the thermoelectric and energetic characteristics. The optimal hot water outlet temperature of 60?80 ?C and discharging pressure of around 16 MPa improved the efficiency by 1.7%. In addition, two different configurations of the thermoelectric generator were presented based on the effective cold energy utilization of the air turbine exhaust. The economic analysis indicated that compared with the organic Rankine cycle and Kalina cycle, the use of thermoelectric generator had economic advantage with a payback period of 2.99 years at an investment cost of $10703.