Influence of external supply of low-grade heat on thermal efficiency of sCO2 power cycles

Abstract

The effect of supply of additional external low-grade heat on overall thermodynamic efficiency is considered using the example of a cycle with a two-stage pressure increase by a compressor and a pump (by analogy with the Allam cycle). The influence of the cycle architecture in terms of organizing the heat fluxes in the pressure boosting system on thermal efficiency is also considered. The analysis is performed in a wide range of initial parameters. It has been determined that an increase in the CO2 temperature at the inlet to the main regenerator due to the supply of external low-grade heat for every 25°C leads to an increase in the cycle efficiency by 2%.