塔式太阳能辅助超超临界燃煤电站耦合方案研究

Research on Coupling Scheme of Tower-Type Solar Energy Assisted Ultra-Supercritical Coal Fired Units

为了充分的利用塔式太阳能集热场的能量,提出将塔式太阳能集热场与超超临界燃煤机组耦合的新型发电系统。太阳能可取代的锅炉受热面为省煤器段、低温过热段、一次再热器蒸汽低温段,结合能量梯级利用原理,提出4种耦合方案,通过Ebsilon热力系统仿真软件进行建模和分析。对于使用二代熔融盐的塔式太阳能热电站与超超临界参数燃煤机组的耦合方案进行研究比较,结果表明:使用太阳能的热量加热锅炉尾部烟道受热面内流经的工质最适宜。同时,集热场中的熔融盐给水换热器与省煤器并联、熔融盐蒸汽换热器与一次低温再热器并联的效果最好。相较于原机组,可提高1.98%的机组热效率和1.7%的机组效率,并降低9.41g/(kW·h)的机组供电标准煤耗率。

In order to make full use of the energy of the tower-type solar energy collection field,a new power generation system coupling the tower-type solar energy collection field with the ultra-supercritical coal-fired unit is proposed.The boiler heating surface that can be replaced by solar energy are:economizer section,low temperature superheating section and primary stage repeated steam low temperature section.Four coupling schemes are proposed according to the principle of energy cascade utilization.Modeling and analysis were carried out by Ebsilon thermal system simulation software.The coupling scheme of the tower-type solar thermal power station using the second generation molten salt and the ultra-supercritical parameter coal-fired unit is studied and compared,and the conclusion is that the working medium flowing through the heating surfaces of the boiler rear pass is most suitable to use the solar heat.At the same time,the effects of parallel connection between the molten salt-feed water heat exchanger and economizer and between the molten salt-steam heat exchanger and the low temperature primary stage reheater are the best.Compared with the original unit,the thermal efficiency and the exergic efficiency of the unit can be increased by 1.98%and 1.7%respectively,and the standard coal consumption rate of the unit power supply can be reduced by 9.41 g/(kW·h).