塔式太阳能辅助燃煤发电系统太阳能贡献度研究

Study on Solar Contribution of Solar Tower Aided Coal-fired Power Generation System

塔式太阳能辅助燃煤发电是将塔式太阳能所获得的热量与燃煤电站相同品位的能量相耦合,借助燃煤电站的发电系统,实现太阳能热的间接发电,该方法可以省却单纯塔式太阳能热发电所需的汽轮机、发电机和回热换热器等部件,从而降低太阳能热发电的初投资。由于太阳能热在系统中间接发电,如何准确评价太阳能在发电过程中的贡献度值得深入研究。基于热力学第二定律和热经济学基本原理,对塔式太阳能辅助燃煤发电系统中太阳能的贡献度进行研究,厘清太阳能热在系统中的分布关系,得出太阳能热的实际发电量和由于太阳能设备的投入而增加的度电成本。最后对某600 MW塔式太阳能辅助燃煤发电系统进行案例分析,验证该方法的可行性。该塔式太阳能辅助燃煤发电系统中,太阳能的发电量占4.24%,而其度电成本中太阳能所占比例仅有0.91%。

Solar tower aided coal-fired power generation（ STACFPG） is the coupling of thermal energy collected by solar tower system and the same grade energy of coal-fired power system. With the help of coal-fired power generation system,it makes indirect solar thermal power generation possible which can save turbines,generators,heat exchangers and other components in solar tower power generation system,thereby reducing investment in solar thermal power generation. Evaluation of solar contribution to the STACFPG is worthy of being studied because of the indirect power generation of solar thermal. Based on the theory of the second law of thermodynamics and thermoeconomics,the solar contribution to STACFPG is studied and the distribution of solar thermal in STACFPG is clarified. The actual solar thermal generation capacity and the increase of cost per k W·h due to investment in solar equipment are obtained. To verify the feasibility of this evaluation method,a case study of 600 MW STACFPG is carried out. In such STACFPG,the power generation of solar is 4. 24%,and the proportion of solar energy in cost per k W·h generation is only 0. 91%.