冷热电联产(combined cooling,heat and power,CCHP)系统的效率评价指标对其优化设计、经济运行等至关重要。基于小功率燃气轮机为核心的CCHP系统基本元件的变工况典型解析特性,对比分析了CCHP系统当量火用效率、经济火用效率、总能利...冷热电联产(combined cooling,heat and power,CCHP)系统的效率评价指标对其优化设计、经济运行等至关重要。基于小功率燃气轮机为核心的CCHP系统基本元件的变工况典型解析特性,对比分析了CCHP系统当量火用效率、经济火用效率、总能利用率、节能系数等"效率"形式及其影响因素。采用不同的效率指标评价以小功率燃气轮机为原动力的2类CCHP系统的全工况性能,以说明不同效率指标的差异。分析表明,前述效率形式都不能给出完全合理的评价结果。但相对而言,节能系数能比较合理评价文中所述两种CCHP系统的优劣,但部分评价结论仍存商榷之处;CCHP系统的部件匹配及经济运行,可综合按全工况节能系数及经济火用效率来评价。展开更多
Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this...Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is wellknown that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal,coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and spontaneous combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on spontaneous combustion of coal and coal mine fires. Within this framework, the generally used spontaneous combustion techniques to predict the spontaneous combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the spontaneous combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.展开更多
文摘冷热电联产(combined cooling,heat and power,CCHP)系统的效率评价指标对其优化设计、经济运行等至关重要。基于小功率燃气轮机为核心的CCHP系统基本元件的变工况典型解析特性,对比分析了CCHP系统当量火用效率、经济火用效率、总能利用率、节能系数等"效率"形式及其影响因素。采用不同的效率指标评价以小功率燃气轮机为原动力的2类CCHP系统的全工况性能,以说明不同效率指标的差异。分析表明,前述效率形式都不能给出完全合理的评价结果。但相对而言,节能系数能比较合理评价文中所述两种CCHP系统的优劣,但部分评价结论仍存商榷之处;CCHP系统的部件匹配及经济运行,可综合按全工况节能系数及经济火用效率来评价。
基金The work presented in this paper is part of a PhD research study in the School of Mining Engineering at the University of the Witwatersrand,Johannesburg,South Africa.
文摘Coal oxidation at low temperatures is the heat source liable for the self-heating and spontaneous combustion of coal. This phenomenon has imposed severe problems in coal related industries. Attempts to understand this phenomenon by previous researchers have provided significant progress. It is wellknown that coal oxidation at low temperatures involves oxygen consumption and formation of gaseous and solid oxidation products. This process is majorly influenced by temperature, oxidation history of coal,coal properties, particle size distribution of the coal, etc. The current understanding of the phenomenon of self-heating and spontaneous combustion of coal is discussed along with the different experimental and numerical models established to predict self-heating characteristics of coal. This paper focuses on the global position of the study carried out by academics, research institutes and industries on spontaneous combustion of coal and coal mine fires. Within this framework, the generally used spontaneous combustion techniques to predict the spontaneous combustion liability of coal were evaluated. These techniques are well-known in their usage, but no specific method has become a standard to predict the spontaneous combustion liability. Further study is still needed to indicate a number of impending issues and to obtain a more complete understanding on the phenomenon.
