Power cycles for waste heat recovery from medium to high temperature flue gas sources - from a view of thermodynamic optimization
Power cycles for waste heat recovery from medium to high temperature flue gas sources - from a view of thermodynamic optimization
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中高温烟气源余热回收的动力循环——从热力学优化的角度
DOI：
10.1016/j.apenergy.2016.08.007
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发表时间：
2016
期刊：
影响因子：
11.2
通讯作者：
Wang Huaixin
中科院分区：
文献类型：
--
作者：
Li Chengyu;Wang Huaixin
工业生产过程中产生的大量废热为废热回收（WHR）提供了机会。选择了几个案例研究，使用烟道气作为热源，这是一个相当宽的源温度范围（200-700 °C）的代表。WHR的目标函数是指净功率输出最大化。为了寻求不同热源条件下循环结构、流体和循环参数的最佳组合，进行了以下研究。不同类型的动力循环（例如，兰金循环、跨临界循环和联合循环）以及不同的循环配置（例如，饱和或过热，有或没有再生器）。为了弥补常规循环在某些情况下的缺陷，提出了一种新型的改进型跨临界CO2循环和两种联合循环设计。在有机物中进行工作流体选择。在参数优化后，对不同循环进行了对比分析。结果表明，回热式有机跨临界循环在热源温度为500 °C时输出功率最大，不同热源温度下的最佳工质不同。改进的跨临界CO2循环在500-600 °C的源温范围内表现出令人满意的性能。一个联合循环在源温度高于600 °C时产生最大功。传统的蒸汽朗肯循环由于与显热源的热匹配不好，在源温低于500 °C时性能较差。在源温度为700 °C时，蒸汽朗肯循环表现出令人满意的性能，并产生接近联合循环的功率输出。
Large quantities of waste heat generated during industrial production offer an opportunity for waste heat recovery (WHR). Several case studies are selected using flue gas as heat source, which are representative of a fairly wide range of source temperature (200–700 °C). The objective function of WHR refers to maximization of net power output. With a view to seeking an optimal combination of cycle configuration, fluid and cycle parameters under different heat source condition, the following researches have been performed. Different types of power cycles (e.g., Rankine cycle, transcritical cycle and combined cycle) as well as different cycle configurations (e.g., saturated or superheating, with or without regenerator) are evaluated. In order to compensate the defects of conventional cycles in some case studies, a novel improved transcritical CO2cycle and two combined cycle designs are presented. Working fluid selection among the organics is performed. After the parametric optimization, comparison and analysis are carried out among different cycles. Results indicate that the regenerative organic transcritical cycle produces the maximum power output at source temperatures up to about 500 °C, and different optimum working fluids are obtained under different heat source temperature. The improved transcritical CO2cycle shows satisfying performance in source temperature range of 500–600 °C. One combined cycle produces the largest work at source temperature above 600 °C. The traditional steam Rankine cycle shows bad performance at source temperature below 500 °C due to its bad thermal matching with sensible source. At source temperature of 700 °C, steam Rankine cycle shows satisfying performance, and produces a power output close to that of the combined cycle.