Analysis on energy saving potentials of overheat recovery of steam extractions for double-reheat power unit
Thermal Power GenerationVol. 46, Issue 8, Pages: 49-53(2017)
更新时间:2025-05-30
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Analysis on energy saving potentials of overheat recovery of steam extractions for double-reheat power unit
作者机构:
西安交通大学动力工程多相流国家重点实验室
作者简介:
基金信息:
DOI:
CLC:TM621.2
Published:2017
稿件说明:
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LIU Ming, ZHAO Yongliang, WANG Chaoyang, et al. Analysis on energy saving potentials of overheat recovery of steam extractions for double-reheat power unit[J]. Thermal Power Generation2017, 46(8): 49-53.
DOI:
LIU Ming, ZHAO Yongliang, WANG Chaoyang, et al. Analysis on energy saving potentials of overheat recovery of steam extractions for double-reheat power unit[J]. Thermal Power Generation2017, 46(8): 49-53.DOI:
Analysis on energy saving potentials of overheat recovery of steam extractions for double-reheat power unit
摘要
再热对给水回热效果有削弱作用
二次再热机组的蒸汽过热度较大
造成的回热过程不可逆损失也更大。分析大过热度回热系统抽汽参数可知
这些过热能量可回收用于锅炉工质和送风加热过程
从而等效降低蒸汽循环吸热量
提高系统效率。为此
本文结合某660 MW二次再热机组
基于热平衡计算模型和?分析模型
对抽汽过热能量回收的节能潜力展开定量研究。结果表明:该机组第5级—第10级加热器抽汽过热度很大
达118~311℃
将这些加热器过热能量全部回收用于锅炉本体
节煤量可达3.59 g/(k W·h);通过抽汽过热能量回收
可提高第5级—第10级加热器的?效率。此外
对过热能量回收系统进行了初步设计
为二次再热机组的系统构型优化提供依据。
Abstract
Reheating weakens the effectiveness of feedwater heat regenerative cycle. For the double-reheat power unit
the irreversible exergy loss of the regenerative heaters gets greater due to the higher superheat degree of steam extractions. Considering the parameters of steam extractions of the regenerative system
these overheats could be used by the boiler to heat the working fluid and feeding air
which will decrease the steam cycle absorption and increase the system efficiency equivalently. Therefore
with a reference case of 660 MW double-reheat power unit
the energy saving potentials of steam extractions overheat recovery were analyzed
based on the energy and exergetic balance models. The results show that
the superheat degrees of No.5 to No.10 steam extractions are very high
about 118 ℃ to 311 ℃. If the overheats of the No.5 to No.10 steam extractions could be recovered to the boiler
the standard coal consumption rate for power generation could be decreased by 3.59 g/(k W·h). Exergetic analysis show that the exergetic efficiency of No.5 to No.10 heaters were increased. Moreover
the overheat recovery system was preliminarily designed. The aim of this paper is to provide fundamentals for the optimization of doublereheat power plants.