Thermodynamic performance of new thermofluidic feed pumps for Organic Rankine Cycle applications
Thermodynamic performance of new thermofluidic feed pumps for Organic Rankine Cycle applications
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DOI：
10.1016/j.apenergy.2015.10.004
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发表时间：
2016
期刊：
影响因子：
11.2
通讯作者：
E. Richardson
中科院分区：
文献类型：
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作者：
E. Richardson
这项研究开发了热流体泵技术，它是由热量驱动的，而不是由电力或机械驱动的。目的是通过使用最近提出的热流体泵，提高有机朗肯循环的热回收性能。热流体泵承诺低成本，高可靠性，并且，由于它不消耗膨胀机产生的任何电力，提高了投资回报。以前没有报道过新型热流体泵的性能数据，因此推导了一个热力学模型，并用于评估表征泵运行及其对整体循环效率的影响的性能指标。然后开发和分析改进的泵配置。提出了一种提高循环热效率的两级泵结构。为了获得与机械给水泵相似的锅炉效率，还提出了一种节能器。研究表明，当中间蒸发器无净热量输入时，两级泵的循环效率最高。由此产生的热效率超过了使用理想的机械泵所能获得的最佳效率。在100°C以下的低温循环中，两级热流控泵实现的循环效率的相对提高是最大的，因为在这种情况下，回功比通常较高，而机电给水泵的效率较差，循环效率的相对提高可达30%。
This study develops thermofluidic pump technology that is powered by heat, rather than by electrical or mechanical power. The objective is to improve the performance of heat-recovery by Organic Rankine Cycles, by using a recently-proposed thermofluidic pump. The thermofluidic pump promises low-cost, high-reliability, and, since it does not consume any of the power produced by the expander, improved return on investment. No performance data for the new thermofluidic pump have been reported previously, therefore a thermodynamic model is derived and used to evaluate performance metrics that characterise pump operation and its impact on the overall cycle efficiency. Improved pump configurations are then developed and analysed. A two-stage pump configuration is presented that enhances the thermal efficiency of the cycle. An economiser is also proposed in order to obtain boiler efficiencies similar to those for mechanical feed pumps. It has been shown that the cycle efficiency with the two-stage pump is maximum when there is no net heat input in the intermediate evaporator. The resulting thermal efficiency exceeds the best-possible efficiency that could be obtained by using anidealmechanical pump. The relative improvement in cycle efficiency achieved with the two-stage thermofluidic pump is greatest for low-temperature cycles operating below 100 °C, for which the back work ratio is usually higher and the efficiencies of electro-mechanical feed pumps are poorer – yielding a relative increase of the cycle efficiency by up to 30%.