集成太阳能热化学过程的混合动力系统

Thermodynamics Analysis on Combined Thermochemical of Solar Energy and Hybrid power System

提出太阳能热驱动甲醇裂解反应制取合成气,联合高温固体氧化物燃料电池–均质压燃内燃机的清洁高效低碳热力系统。结果表明,在设计工况下,热化学效率63%,混合动力发电效率48.7%,太阳能净发电效率30.7%,系统的?效率为40.25%。不可逆损失分布由大到小依次为内燃机,燃料电池空气预热器,太阳能热化学过程,排烟损失,高温固体氧化物燃料电池,甲醇预热器和内燃机空气预热器。相较于传统混合动力系统,太阳能热化学过程转移了固体氧化物燃料电池的部分不可逆损失。太阳能辐照强度从300 W/m^(2)增加至800 W/m^(2),热化学效率从52%升高至63%,太阳能净发电效率由25.3%增长至30.7%。燃料利用率从0.5增加至0.85时,内燃机功率输出占比不断减小至15.6%,混合动力单元的发电效率从45%增加至50%。

A novel integrated system has been proposed combining intermediate-temperature ther-mochemical solar energy conversion with a Hybrid Solid Oxide Fuel Cell-Internal Combustion Engine(SOFC-ICE)system.Methanol serves as an alternative fuel.It undergoes cracking to syngas within the solar collector operating at temperatures ranging from 250℃ to 300℃,subsequently supplying power plants for electricity generation.Mathematical models were developed for the 0-D simula-tion of the thermochemical reaction unit,solid oxide fuel cell unit,and homogeneous compression charge ignition engine unit.The design analysis revealed impressive efficiencies:the solar-to-chemical efficiency reached 72.9%,and the hybrid SOFC-ICE system demonstrated the power and exergy ef-ficiency of 48.7%and 40.25%,respectively.The overall solar-to-chemical-to-power efficiency was found to be 30.7%.Irreversibility within the components followed a descending order:the internal combustion engine,SOFC air preheater,solar-to-chemical process,exhaust loss,solid oxide fuel cell power generation,methanol preheater,and engine air preheater.Compared with the traditional hy-brid SOFC-ICE system,the thermochemical unit mitigates exergy losses associated with the external reformer.Furthermore,with increasing solar irradiance from 300 W·m^(−2) to 800 W·m^(−2),the solar-to-chemical efficiency rose from 52%to 63%,and the solar-to-chemical-to-power efficiency increased from 25.3%to 30.7%.As fuel utilization increased from 0.5 to 0.85,the engine power output ratio reduced to 15.6%,resulting in a notable enhancement of the power efficiency of hybrid system from 45%to 50%.