摘要
为了更准确地计算余热引入电厂热力系统的节能量,在等效热降法的基础上,研究了余热利用所致汽轮机相关级组的变工况运行特性,提出了机组内功率增量计算的新方法.结合流体输运特性,提出了余热利用所致循环泵、凝结水泵的厂用电增量的估算方法.以某1 000MW超临界机组为例,计算并分析了余热引入热力系统不同加热器时的汽轮机抽汽参数、内功率和厂用电等热经济性指标.结果表明:余热进入热力系统使汽轮机相关级组处于变工况运行状态,实际内功率增量小于等效热降法的计算结果;余热进入回热加热器的温度水平越高,节能效果越好,但低温省煤器的传热温差越小,投资成本越大.
To accurately calculate the amount of energy saving by introducing residual heat into thermal system of power plants,operating characteristics of relevant turbine stages affected by residual heat application were studied under variable working conditions,and subsequently a new way for calculation of the internal power increment was proposed based on equivalent entropy drop method.Combining with the fluid transport properties,an estimate method for calculating the power increment of circulating pump and condensate pump caused by residual heat application was proposed.Taking a 1 000MW supercritical unit as an example,the extraction parameters,internal power and auxiliary power were analyzed under the introduction of residual heat into different heaters of the thermal system.Results show that the introduction of residual heat into thermal system makes relevant turbine stages work in variable operation conditions,with an actual internal power increment less than the calculated result by equivalent enthalpy drop method;the higher the temperature level of residual heat is,the better the energy saving effect will be,whereas the smaller the heat-transfer temperature difference of the low-temperature economizer is,the higher the investment will be.
出处
《动力工程学报》
CAS
CSCD
北大核心
2014年第5期411-416,共6页
Journal of Chinese Society of Power Engineering
基金
国家自然科学基金资助项目(51376059)
关键词
余热
电厂
热力系统
热经济性
等效热降法
厂用电
residual heat
power plant
thermal system
thermal economy
equivalent entropy drop method
auxiliary power
