Design and evaluation of an integrated CCHP system based on solar thermal supplementary heating and off-peak electrical thermal storage heating
Jiarui Zeng, Shaowu Yin, Lige Tong, Chuanping Liu, Li Wang, Chuan‐Yu Wu
Abstract
Rising demands for heating and cooling, along with the need for grid peak regulation, pose challenges to modern energy systems . Traditional methods such as Combined Cooling, Heating, and Power (CCHP), off-peak thermal storage , and ammonia-water absorption cooling often operate in isolation, making them insufficient to meet the growing demand. Thus, this study introduces an integrated CCHP system that utilizes solar energy and off-peak electricity to enhance grid stability. A case study of a 1000 m 2 office building evaluates turbine and generator steam inlet parameters through sensitivity analyses and multi-objective optimization. The evaluation indicates that, in summer, the system achieves a Coefficient of Performance (COP) of 0.75, with exergy efficiency of 44.74 % and system efficiency of 52.63 %. In winter, the exergy efficiency reaches 63.99 %, and the system efficiency is 82.79 %. The system effectively manages 352.12 kW in summer and 269 kW in winter, saving $23,600 annually in operation and maintenance costs . Additionally, it achieves a Levelized Cost of Storage (LCOS) of $0.17/kWh, surpassing coal-fired and reference CCHP systems in system efficiency.