SCO_(2)布雷顿循环布局的过程特性的现状与评价

Status and Evaluation for Process Characteristics of SCO_(2) Brayton Cycle Layout

为了探究超临界CO_(2)布雷顿循环布局形式对循环性能的总体影响,应用控制变量法和统计学方法分别对简单循环(简单回热循环)、高级循环(再压缩、分级膨胀、再压缩再热循环)和联合循环(联合回热循环和再压缩回热循环组合)进行了分析比较,确定了循环中关键操作参数对循环效率的影响,并对其进行技术评价。结果表明,循环效率随透平进口温度增加而增高,主压缩机进口温度超过CO_(2)临界温度时循环效率下降,分别随主压缩机入口压力、压比和分流比的增加而先升高后下降。从技术角度来看,循环效率与循环布局的复杂性呈正相关。特别是有机朗肯SCO_(2)再压缩回热循环和再压缩再热循环是优选的类型。从经济性角度来看,随着循环复杂度增加,所需成本增加,因此应综合考虑其成本问题。

To explore the influence of SCO_(2) Brayton cycle layouts on cycle performance,simple cycle(simple recuperated cycle),advanced cycle(recompression,split expansion,recompression-reheat cycle),and combined cycle(combined reheat cycle and recompression-reheat cycle)were analyzed and compared by applying the variable-controlling method and statistical methods,respectively.The effects of key operating parameters on cycle efficiency were identified and technically evaluated.It is found that the cycle efficiency increases with the increase of the turbine inlet temperature,decreases when the inlet temperature of the main compressor exceeds the critical temperature of CO_(2),increases and then decreases with the increase of the main compressor inlet pressure,pressure ratio,and split ratio,respectively.From a technical point of view,cycle efficiency is positively correlated with the complexity of cycle layout.In particular,the organic Rankine SCO_(2) recompression reheat cycle and the recompression-reheat cycle are preferred types.From an economic perspective,as the complexity of the cycle increases,the cost also increases.Therefore,the cost should be considered comprehensively to meet the efficiency of the cycle.