壳管式反应器中氢氧化钙/氧化钙热化学反应的数值研究：放热过程分析与太阳能-热化学冷热电联供系统优化

Abstract Thermochemical energy storage technology offers high energy density and long-term storage capability of addressing solar energy intermittency, with calcium hydroxide/calcium oxide systems particularly promising due to abundant raw materials and environmental friendliness. Effects of the exothermic heat transfer mechanisms and operating parameters on shell-tube reactor performance are not well understood, and integration with concentrated solar power systems lacks comprehensive optimization studies. This study aims to systematically investigate the exothermic process and develop an integrated solar-thermochemical combined cooling, heating and power system through advanced modeling and performance optimization. A three-dimensional numerical model coupling heat and mass transfer with chemical reactions was developed, with parametric studies on examining effects of temperature, porosity, steam velocity, and thermal conductivity, followed by system modeling and energy, exergy, economic, and environmental analysis using multi-criteria decision methods. At the optimal operating temperature of 533 Kelvin, the system achieved peak exothermic power of 1600 W with reaction completion of 4400 s, while reduced porosity extended the heat output duration, optimal steam velocity of 0.09 m per second enhanced performance, and improved thermal conductivity along with significantly enhanced heat transfer performance by increasing tube number. The integrated system achieved energy efficiency of 58.98 %, exergy efficiency of 51.35 %, electricity generation of 46.28 megawatt-hours, heating output of 7.08 megawatt-hours, and cooling capacity of 1.39 megawatt-hours with payback period of 15.99 years. This work provides numerical insights for reactor optimization by demonstrating the engineering feasibility of solar-thermochemical combined cooling, heating, and power systems for renewable energy applications.