摘要
以燃气循环作顶循环,超临界二氧化碳(SCO_(2))布雷顿循环作底循环构建了燃气-SCO_(2)联合循环。建立了关键部件的数学模型,分析了循环参数对系统性能的影响,并从分析的角度探索了燃气-SCO_(2)联合循环实现能量梯级利用的理论基础。结果表明:底循环效率随透平入口参数在低压段(14MPa~20MPa)变化明显,高压段(20MPa~26MPa)趋于平缓。高压条件下,提高透平入口温度对联合循环效率增益作用更明显。分流比与最高循环压力存在最佳配比。压缩机入口压力较低时入口温度对热力性能影响较大,随着压缩机入口压力增加,压力逐渐成为主要影响因素。单个再压缩循环余热回收能力有限,为提高能量利用率可增加底循环数量。
This paper uses the gas cycle as the top cycle and the supercritical carbon dioxide(SCO_(2))Brayton cycle as the bottom cycle to construct a gas-SCO_(2)combined cycle.The mathematical model of the key components was established,the influence of the cycle parameters on the system performance was analyzed,and the theoretical basis of the gas-SCO_(2) combined cycle to achieve energy cascade utilization was explored from the perspective of exergy analysis.The results show that the bottoming cycle exergy efficiency varies significantly with turbine inlet parameters in the low-pressure section(14MPa~20MPa),and the high-pressure section(20MPa~26MPa)is generally flat.Under high pressure conditions,increasing the turbine inlet temperature has a more obvious effect on the efficiency gain of the combined cycle.There is just an optimal ratio between the split ratio and the highest circulating pressure.When the compressor inlet pressure is low,the inlet temperature has a greater impact on the thermal performance.As the compressor inlet pressure increases,pressure gradually becomes the main influencing factor.The waste heat recovery capacity of a single recompression cycle is limited,and the number of bottom cycles can be increased to improve energy utilization.
作者
吴佳华
WU Jia-hua(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)
出处
《汽轮机技术》
北大核心
2022年第1期38-42,共5页
Turbine Technology
基金
大创项目资助(S202110079012)。
