采用压缩储能的新型超临界二氧化碳布雷顿循环塔式太阳能热发电系统性能分析

Performance analysis of a new supercritical carbon dioxide Brayton cycle tower solar thermal power generation system using compressed energy storage

基于超临界二氧化碳(S-CO_(2))布雷顿循环的特点,提出一种新型的采用压缩CO_(2)储能的S-CO_(2)布雷顿循环塔式太阳能热发电系统。该系统利用多余的太阳能将处于临界点附近的CO_(2)压缩至高压状态,在夜间利用燃气锅炉燃烧天然气加热高压的CO_(2),使其进入透平做功,带动发电机发电。通过Ebsilon软件分别建立采用熔盐储热和采用压缩CO_(2)储能的塔式太阳能热发电系统模型,并优化底循环工质,得出最佳效率条件下的运行参数。在此基础上,分析典型日运行工况,计算2个系统的热经济性。结果表明,在储热时长为8 h的情况下,相比熔盐储热系统,新型的采用压缩CO_(2)储能的太阳能热发电系统夏至日日均效率提升0.31%,冬至日日均效率提升0.97%,具有较好的应用前景。

Based on the characteristics of supercritical carbon dioxide Brayton cycle,this paper proposes a new type of S-CO_(2) Brayton cycle tower solar thermal power generation system with compressed CO_(2) energy storage.The system uses excess solar energy to compress CO_(2) near the critical point to a high-pressure state,and uses a gas boiler to burn natural gas at night to heat the high-pressure CO_(2),which then enters the turbine to perform work and drives the generator to generate electricity.This paper uses the commercial software Ebsilon to establish tower solar thermal power generation system model with molten salt heat storage and compressed CO_(2) energy storage respectively,and the bottom cycle working fluid is optimized to obtain the operating parameters under the best efficiency conditions.On this basis,the typical daily operating conditions are analyzed,and the thermal economy of the two systems is calculated.The results show that,when the heat storage time is 8 hours,compared with the daily average efficiency of the molten salt heat storage system,that of the new solar thermal power generation system using compressed CO_(2) energy storage increases by 0.31%during the summer solstice and by 0.97%during the winter solstice.The new system has good application prospects.