中文摘要：

以木片气化气为燃料,分析了IT-SOFC/GT混合动力系统运行性能,研究了水蒸气量的改变对重整器重整特性、燃料电池电化学特性以及混合系统热力学性能的影响。结果表明：在设计工况下,混合动力系统的发电效率高达59.24%,具有较好的系统性能。水蒸气增加,反应温度降低,导致CH_4重整反应平衡常数降低,不利于CH_4向H_2转化;CO水气变换反应平衡常数随温度降低而增加,有利于CO转化,但综合产氢量减少。燃料电池的电极和欧姆极化随水蒸气的增加而增加,能斯特电势减少,电池的输出功率和发电效率减少。混合系统的输出功率和发电效率均随水蒸气量的增加而减少,发电效率从61%降到56.91%。但从重整器、电池堆以及整个系统的安全运行方面考虑,保持较高的水蒸气量非常重要。

英文摘要：

Using biomass gas,the operating characteristic of an intermediate-temperature solid oxide fuel cell（IT-SOFC） and a gas turbine（GT） hybrid system was investigated.The effects of steam on the thermodynamic performances of reformer,fuel cell,gas turbine and hybrid system are studied.Results indicate that the electrical efficiency is 59.24%under the design condition.As the steam increases,the reforming temperature decreases,which leads to CH_4 reforming reaction equilibrium constant decreases,and the reaction will be suppressed.The water gas shift reaction equilibrium constant increases with the decrease of the temperature.But the total amount of H_2 shows a decreasing trend.With the steam increases,the fuel cell electrode and ohmic polarization losses increase,Nernst potential decreases,the output power and electrical efficiency show a decreasing trend.And then the hybrid system output power and electrical efficiency decrease.The electrical efficiency decreases from 61%to 56.91%.In consideration of operation security of reformer,fuel cell stack and the hybrid system,maintaining a high value of the steam is very important.