A comparison of two low grade heat recovery options
A comparison of two low grade heat recovery options
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DOI：
10.1016/j.applthermaleng.2012.04.035
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发表时间：
2011-10
影响因子：
6.4
通讯作者：
Conor J. Walsh;P. Thornley
中科院分区：
文献类型：
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作者：
Conor J. Walsh;P. Thornley
低品位热 (LGH) 回收是提高工业能源效率和减少相关温室气体排放的一种方法。有机朗肯循环 (ORC) 和冷凝锅炉是可用于回收低品位热量 (<250 °C) 的两种选择。本文评估了与这两种技术相关的生命周期温室气体减排影响和折扣投资回收期。通过 ORC 运行发电每年可节省约 11 kt 二氧化碳，但焦化过程的高碳强度意味着这对整个过程生命周期的影响可以忽略不计 (<1%)。然而，如果所产生的电力抵消了外部购买电力，则可实现 3 至 6 年的有利经济投资回收期。木片锅炉内的冷凝锅炉的运行减少了实现增加的热输出所需的燃料。热效率的提高将生命周期影响减少了 11% 至 21%，投资回收期低至 1.5-2 年，具体取决于冷凝器类型和木材供应链。这两个案例研究强调了确定满足多重环境、经济和更广泛目标的 LGH 回收解决方案的难度。
Low grade heat (LGH) recovery is one way of increasing industrial energy efficiency and reducing associated greenhouse gas emissions. The organic Rankine cycle (ORC) and condensing boiler are two options that can be used to recover low grade heat (<250 °C). This paper assesses the lifecycle greenhouse gas reduction impacts and discounted payback periods associated with both technologies. Generation of electricity through the operation of the ORC saves approximately 11 kt of CO2annually, but the high carbon intensity of the coking process means this has a negligible influence (<1%) on the overall process lifecycle impacts. However, if the electricity generated offsets the external purchasing of electricity this results in favourable economic payback periods of between 3 and 6 years. The operation of a condensing boiler within a woodchip boiler reduces the fuel required to achieve an increased thermal output. The thermal efficiency gains reduce the lifecycle impacts by between 11 and 21%, and reflect payback periods as low as 1.5–2 years, depending on the condenser type and wood supply chain. The two case studies are used to highlight the difficulty in identifying LGH recovery solutions that satisfy multiple environmental, economic and wider objectives.