中低温太阳能品位间接提升及系统集成

THE INDIRECT UPGRADING OF LOW/MID TEMPERATURE SOLAR HEAT AND ITS SYSTEM INTEGRATION

本文提出了中低温太阳热能品位间接提升的概念、方法和系统集成，其核心是热集成和热化学转换的有机结合。在所提出的太阳能和化石能源综合互补的化学回热循环系统（SOLRGT）中，中低温太阳热能首先提供蒸汽蒸发潜热从而转化为蒸汽内能；其次通过蒸汽参与重整反应进一步转化为合成气化学能，实现品位提升；最后得以在高效的燃气轮机系统中实现热功转换。由于太阳能的引入，燃气轮机透平排气余热回收部分的热匹配得到极大改善，并减少了化石能源消耗；同时，蒸汽产率的增加有助于增进系统化学回热和物理回热收益。系统中太阳能热转功净效率可达26．5％；和常规化学回热循环相比，化石能源节约率可达20％-30％，实现相应数量的C02减排，系统中实现了中低温太阳能的高效热功转换和与化石燃料的梯级互补。

This paper presents the concept of indirect upgrading of low/mid level solar heat, and demonstrates the indirect upgrading of solar heat and its high efficiency conversion into electricity with a novel solar hybrid system integration. The proposed hybrid power system consists of an intercooled chemically recuperated gas turbine （CRGT） cycle, in which the low/mid temperature solar thermal energy is first transformed into the latent heat of vapor supplied to a reformer and then via the reforming reactions to the produced syngas chemical exergy. The solar-driven steam production helps to improve both the chemical and thermal recuperation in the system. Based on the well established technologies including steam reforming and low/mid level solar energy collection, the hybrid system exhibits promising performance： the net solar to electricity efficiency, based on gross solar thermal energy to the collector, can be expect a typical value of 26.5%. In comparison to conventional CRGT system without solar assist, 20%-30% of fossil fuel saving and corresponding mitigation of CO2 emission are feasible.