摘要
针对我国西北地区太阳能和低阶煤资源丰富的特点,提出一种利用太阳能预干燥低阶煤的发电系统.以某典型600 MW超临界机组为例,通过建立太阳能集热单元和低阶煤预干燥单元的热平衡模型,分析了太阳能预干燥低阶煤后煤的质量与能量的变化规律,从机组煤耗率和太阳能光电转换效率等角度评估了太阳能预干燥低阶煤发电系统的综合热力性能;并以静态投资回收期作为经济性评价指标,探讨了设备总投资和上网电价变化对机组经济性能的影响.结果表明:利用低品位太阳能预干燥低阶煤可有效降低机组煤耗率,当低阶煤水分由25.0%干燥至10.0%时,煤耗率降低8.9g/(kW·h),同时太阳能光电转换效率可达到25.3%,静态投资回收期仅为4.3a,系统经济效益显著.
As northwest China is rich in solar energy and low-rank coal resources, a low-rank coal fired power generation system was proposed using solar energy integrated low-rank coal pre-drying technology. Taking a typical 600 MW supercritical unit as an object of study, heat balance models were established for the solar collection unit and the low-rank coal pre-drying unit, so as to analyze the changes of the coal mass flow and heat value with and without coal pre-drying, evaluate the comprehensive thermal performance of the proposed system from aspects of coal consumption and solar-to-electric efficiency, and finally to study the effects of total equipment investment and on-grid power tariff on the economic performance of the sys- tem with static investment payback period as the evaluation criteria. Results show that the coal consump- tion rate of the coal-fired power plant could be reduced remarkably by using low-grade solar energy to pre- dry the low-rank coal. As the moisture of low-rank coal reduces from 25.0% to 10.0%, the coal consump- tion rate would be lowered by 8.9 g/（kW · h）, when the solar-to-electric efficiency could reach 25.3% with only 4.3 years of static investment payback period, indicating remakable economic benefit of the sys- tem.
出处
《动力工程学报》
CAS
CSCD
北大核心
2017年第9期757-763,772,共8页
Journal of Chinese Society of Power Engineering
基金
国家重点基础研究发展计划(973计划)资助项目(2015CB251504)
国家自然科学基金资助项目(51476053)
中央高校基本科研业务费专项基金资助项目(2017MS013
2015ZZD10)
关键词
太阳能
低阶煤
预干燥
性能分析
solar energy
low-rank coal
pre-drying
performance analysis
