Performance analysis of a carnot battery system coupled Ca(OH)₂/CaO thermochemical heat storage and coal-fired power plant

TY - JOUR

T1 - Performance analysis of a carnot battery system coupled Ca(OH)2/CaO thermochemical heat storage and coal-fired power plant

AU - Tian, Ran

AU - Xiao, Xiao

AU - Wei, Mingshan

AU - Xu, Qianghui

AU - Han, Wei

AU - Yang, Tao

AU - Shen, Jun

N1 - Publisher Copyright: © 2025 Elsevier Ltd

PY - 2026/1/1

Y1 - 2026/1/1

N2 - To enhance the utilization of renewable energy, accelerate the transition of the role of coal-fired power plants, and reduce carbon emissions, a Carnot battery system integrated thermochemical energy storage and coal-fired power plant is designed and analyzed. This system employs a sCO2 Brayton reverse cycle to transfer electricity to heat, utilizing CaO/Ca(OH)2 as the heat storage material. In the energy release scenario, the hydration reaction releases heat to the reheat steam, thus replacing a portion of the reheat energy. Aspen Plus is used to construct the system and is validated by practical operating data. The thermodynamic analysis shows the coupled system achieves a round-trip efficiency of 51.7 % and an exergy efficiency of 44.6 %. The implementation of the Carnot battery can effectively reduce coal consumption by more than 7.3 %. However, it may elevate the flue gas temperature at the high temperature reheater outlet beyond the operational limits. To address this problem, a feasible boiler heat exchanger area adjustment scheme is proposed based on the heat balance analysis of the boiler. Additionally, the effects of the extraction capacity and pressure on system performance are examined. Regenerative steam at 0.03 MPa with an extraction capacity of 10.0 kg/s represents the optimal selection.

AB - To enhance the utilization of renewable energy, accelerate the transition of the role of coal-fired power plants, and reduce carbon emissions, a Carnot battery system integrated thermochemical energy storage and coal-fired power plant is designed and analyzed. This system employs a sCO2 Brayton reverse cycle to transfer electricity to heat, utilizing CaO/Ca(OH)2 as the heat storage material. In the energy release scenario, the hydration reaction releases heat to the reheat steam, thus replacing a portion of the reheat energy. Aspen Plus is used to construct the system and is validated by practical operating data. The thermodynamic analysis shows the coupled system achieves a round-trip efficiency of 51.7 % and an exergy efficiency of 44.6 %. The implementation of the Carnot battery can effectively reduce coal consumption by more than 7.3 %. However, it may elevate the flue gas temperature at the high temperature reheater outlet beyond the operational limits. To address this problem, a feasible boiler heat exchanger area adjustment scheme is proposed based on the heat balance analysis of the boiler. Additionally, the effects of the extraction capacity and pressure on system performance are examined. Regenerative steam at 0.03 MPa with an extraction capacity of 10.0 kg/s represents the optimal selection.

KW - Boiler heat balance

KW - Boiler improvement

KW - Carnot battery

KW - Efficiency optimization

KW - Exergy analysis

KW - Thermochemical energy storage

UR - https://www.scopus.com/pages/publications/105009899475

U2 - 10.1016/j.renene.2025.123922

DO - 10.1016/j.renene.2025.123922

M3 - Article

AN - SCOPUS:105009899475

SN - 0960-1481

VL - 256

JO - Renewable Energy

JF - Renewable Energy

M1 - 123922

ER -