粮食热风干燥系统火用评价理论研究

为揭示粮食干燥系统能量损耗的本质,该文针对粮食热风干燥系统特征、 基准点、干燥室焓 结构及 效率进行深入地理论分析,明确了粮食的含水率是状态函数,确立了干燥系统起算 的基准点,提出了 基准函数,并在湿空气焓—含湿量图上绘出其变化过程,通过 效率分析,揭示了能的"量"与"质"的匹配关系。该文为深一步研究能量损耗的原因、部位,探讨高效节能干燥的途径以及工艺设计、制订合理地系统评价标准,提供了科学地分析方法。

Exergy evaluation theory of hot air drying system for grains

This paper theoretically analyzes the features of hot air drying system for grain, exergy reference point, enthalpy and exergy structure of drying chamber and exergy efficiency,in order to reveal the nature of energy consumption of grain drying system. The results shows that the moisture content of grain is a state function, establishes the exergy reference point of drying system for starting calculation, proposes exergy benchmark functions and plots the changing process of moist air on its psychrometric chart. The paper also reveals the matching relation between "quantity" and "quality" by analyzing the exergy efficiency. It lays a foundation for further study of the reasons and position of energy loss. Additionally, it provides scientific analysis methods to investigate the approach and the process design of energy efficient drying system and to develop reasonable evaluation criteria for the system.