摘要
超临界二氧化碳循环结构多样。详细讨论回热压缩过程对循环效率的影响。通过热力学第一定律,推导发现再压缩循环的热效率可以分成2部分表示,一部分的效率与单回热布雷顿循环效率相同,另一部分为100%,这2部分的份额分别与主、辅压缩机内流量份额相同。依据这一发现,再压缩循环可被看作是在单回热布雷顿循环的基础上叠加一个效率为100%的循环。受这一发现的启发,在再压缩循环的基础上进一步叠加效率为100%的循环,则构建出三级回热压缩循环。然而上述构造方法需满足2个构造条件:端点温差条件和净输出功条件。当满足构建条件时,就能通过这种方法,获得更高一级的回热压缩循环。且随回热压缩级数提高,循环效率就会提高。
Supercritical carbon dioxide(S-CO2)cycle has various structures.This paper discussed in detail the influence of the regenerative-compression process on thermal efficiency.Through the first law of thermodynamics,it is found that the thermal efficiency of the re-compression cycle(RC)can be expressed in two parts.The efficiency of one part is the same as that of single cycle Brayton cycle,and the other part is 100%.The share of the two parts is the same as that of the flow rate in the main and auxiliary compressors.According to this finding,it can be seen that a cycle with 100%efficiency is added to the SC to form the RC with higher efficiency.According to this idea,on the basis of the RC,a cycle with an efficiency of 100%can be added to build a three-stage regenerative-compression cycle(TC),which has higher thermal efficiency.However,there are two construction conditions to be satisfied:the terminal temperature difference condition and the work output condition.As long as these two conditions are satisfied at the same time,a regenerative-compression cycle with higher stage and higher efficiency can be constructed.
作者
李航宁
孙恩慧
徐进良
LI Hangning;SUN Enhui;XU Jinliang(The Beijing Key Laboratory of Multiphase Flow and Heat Transfer for Low Grade Energy Utilization(North China Electric Power University),Changping District,Beijing 102206,China)
出处
《中国电机工程学报》
EI
CSCD
北大核心
2020年第S01期211-221,共11页
Proceedings of the CSEE
基金
国家自然科学基金创新研究群体科学基金(51821004)
关键词
超临界二氧化碳
布雷顿循环
热效率
热力学
循环结构优化
多级回热压缩
supercritical carbon dioxide(S-CO2)
Brayton cycle
thermal efficiency
thermodynamics
cycle structure optimization
multi-stage regenerative-compression
