基于CO_(2)混合工质动力循环的塔式太阳能热发电系统四季性能分析  

PERFORMANCE ANALYSIS OF SOLAR POWER TOWER SYSTEM WITH CO_(2)-BASAED MIXTURES AT TYPICAL DAYS OF FOUR SEASONS

作　　者：梁娅冉 蔺新星 苏文 欧少端[1] 邢令利 Liang Yaran;Lin Xinxing;Su Wen;Ou Shaoduan;Xing Lingli(School of Energy Science and Engineering,Central South University,Changsha 410083,China;China Three Gorges Corporation Science and Technology Research Institute,Beijing 100038,China;School of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201,China)

机构地区：[1]中南大学能源科学与工程学院,长沙410083 [2]中国长江三峡集团科学技术研究院,北京100038 [3]湖南科技大学化学化工学院,湘潭411201

出　　处：《太阳能学报》2023年第9期257-263,共7页Acta Energiae Solaris Sinica

基　　金：国家自然科学基金(52106037);福建省新能源发电与电能变换重点实验室开放基金(KLIF-202106);中国长江三峡集团项目(202003024)。

摘　　要：为高效转换塔式太阳能系统的聚光热量,将混合工质(CO_(2)/R290、CO_(2)/R600a和CO_(2)/R601a)应用于再压缩动力循环,建立塔式太阳能热发电系统的热力模型,并基于典型日(春分、夏至、秋分、冬至)的辐照条件对系统热力性能进行分析比较。结果表明:在混合工质不可燃的质量分数范围内,随着CO_(2)质量分数的增加,3种混合工质的系统热效率、效率和发电量均先升高后降低,最优质量分数分别为0.7/0.3、0.8/0.2和0.8/0.2。在3种混合工质中,CO_(2)/R290(0.7/0.3)的系统性能最佳,春分的系统热效率为18.99%,发电量为17.1 MWh。在不同典型日下,夏至系统热效率和效率略低于冬至,但其发电量最高。基于3种混合工质探究透平进口温度、循环最低温度、高温熔盐温度和分流比对系统性能的影响,结果表明,系统存在最佳分流比使热效率和发电量最高,相应分流比的范围为0.70~0.75。In order to efficiently convert the concentrated heat of solar power tower system,three mixtures(CO_(2)/R290,CO_(2)/R600a and CO_(2)/R601a)are applied to the recompression power cycle.An integrated model is established for the solar power tower system,and the corresponding thermal performances are analyzed and compared under the irradiation conditions of typical days in four seasons(March 20,June 21,September 23 and December 21).The obtained results show that:in the mass fraction range of CO_(2)-based mixture with nonflammability,as the CO_(2)mass fraction increases,the system thermal efficiency,exergy efficiency and generated power of the mixtures increase first and then decrease.The optimal mass fractions are 0.7/0.3,0.8/0.2 and 0.8/0.2,respectively.Among these three mixtures,CO_(2)/R290(0.7/0.3)has the best performances with the thermal efficiency 18.99%and generated power 17.1 MWh at Vernal Equinox.Under different typical days,the thermal efficiency and exergy efficiency of Summer Solstice are slightly lower than those of Winter Solstice,but the generated power is the highest.Furthermore,based on the three CO_(2)-based mixtures,effects of turbine inlet temperature,minimum cycle temperature,hot molten salt temperature and split ratio on system performances are also investigated.It’s found that there exists an optimal split ratio to achieve the highest thermal efficiency and generated power.For the recompression power system,the optimal split ratio is in the range of 0.70-0.75.

关 键 词：塔式太阳能热发电系统 CO_(2)混合工质 再压缩动力循环 热力性能 

分 类 号：TK514[动力工程及工程热物理—热能工程]