低温热能高效利用途径分析

低温热能总量巨大,对其高效利用在节能减排、能源结构调整等方面的意义重大.低温热能已在我国工业过程中初步利用,但尚存改进与优化空间.未来工业过程中的低温热能将呈现出新的特点与趋势,低温热能的利用途径也需相应发生变化.提出低温热能利用的总体原则,即“将合适的能源用在合适的地方”,追求整体效益最大化,并从五个层次进行了解释；提出低温热能利用具体实施中的三步骤技术路线；围绕低温热能利用中的关键技术,进行原理和性能改进方向的讨论,包括低温热能发电技术、热泵技术,以及系统的模拟、评价、优化和运行控制技术.展望了更高层次的能源系统优化,将优化原则从“温度对口,梯级利用”拓展到“温度、压力对口,梯级利用；成分、体量对口,分级转化；地域、用能形式对口,供需双向协同”,以实现能源资源在更高系统层面的高效综合利用.

Analysis of Effective Utilization of Low-temperature Heat

Low-temperature heat is a big source of energy.An efficient use of such energy source will be of great significance to energy saving,emission reduction and energy mix adjustment.Low-temperature heat has already been used in domestic industrial sectors and there is still room for further improvement and optimization.The application of low-temperature heat in the industrial sector is exhibiting new features and trends and accordingly the methods for utilizing low-temperature heat should also change.This article proposes a general principle for low-temperature heat utilization,i.e.,using the appropriate energy in the appropriate place.This principle is aimed to maximize overall efficiency,which is explained at five levels in the article.Three steps are recommended to utilize low-temperature heat.The article also discusses the working principles of key technologies used in low-temperature heat utilization as well as possible improvements to these technologies.These technologies include low-temperature heat-based power generation technology,heat pump technology,and system simulation,assessment,optimization and operation control technologies.The article also envisions higher levels of energy system optimizations,expanding optimization principles from "temperature match and cascade utilization" to "temperature and pressure match,cascade utilization;component and mass match and staged conversion;region and energy utilization pattern match and supply-demand coordination" to achieve an efficient and comprehensive use of energy at a higher system level.