Parametric analysis of a semi-closed-loop linear joule engine generator using argon and oxy-hydrogen combustion
Parametric analysis of a semi-closed-loop linear joule engine generator using argon and oxy-hydrogen combustion
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使用氩气和氢氧燃烧的半闭环线性焦耳发动机发电机的参数分析
DOI：
10.1016/j.energy.2020.119357
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发表时间：
2021
期刊：
影响因子：
9
通讯作者：
Ngwaka U
中科院分区：
文献类型：
--
作者：
Ngwaka U
介绍了一种新型的半闭环直线焦耳发动机发电机(LJEG)，该发电机以Ar为主要工质，以氧气-氢气燃烧为供热方式。LJEG中的直线压缩机和膨胀机采用双作用活塞配置，以最大化功率密度，氧氢-氩反应器具有超高的换热效率，并最终排放零碳、NOx和颗粒排放。拟议的LJEG是在以前的实验室规模LJEG原型的基础上发展起来的，使用空气作为工作介质。通过对比研究，证明了新概念设计的优势；用空气代替空气作为主要工质，提高了系统速度，降低了指示功率，效率提高了60%以上。利用验证后的模型进行了进一步的参数分析，揭示了不同的进排气门正时、压气机/膨胀机直径比、电负荷和工作温度对发动机性能的影响。分析表明，系统效率随进气持续时间的延长而降低，但随膨胀机排气持续时间的延长而提高。功率输出随膨胀机进气持续时间的延长而增大，但其与压缩机和膨胀机直径比的关系取决于膨胀机排气门的正时，在膨胀机进气温度为1073℃时，最大功率输出可达到4.7 kW。系统最佳性能的运行温度也高度依赖于气门定时。压缩机/膨胀机直径比和工作温度的增加对活塞行程长度有不利影响。当压缩机/膨胀机直径比为0.70和0.93时，系统效率分别达到40%和60%的峰值。
The paper introduces a novel semi-closed-loop Linear Joule Engine Generator (LJEG) using argon as the major working fluid and oxy-hydrogen combustion for heat addition. The linear compressor and expander in the LJEG apply double-acting piston configuration to maximise power density, and an oxy-hydrogen-argon reactor has ultra-high heat transfer efficiency and emits ultimate zero carbon, NOx, and particulate emissions. The proposed LJEG is developed from a previous lab-scale LJEG prototype using air as the working fluid. A comparison study demonstrates the advantages of the new conceptual design; substituting air with argon as the major working fluid resulted in increased system speed, decreased indicated power, and over 60% indicated efficiency improvement. A further parametric analysis was conducted using a validated model to reveal the influence of different intake and exhaust valve timing, compressor/expander diameter ratio, electric load, and operating temperature. The analysis shows that the system efficiency decreases with the extended intake duration, but it could be improved with the extension of expander exhaust duration. Power output increases with longer expander intake duration, however, its relationship with diameter ratio of compressor and expander is dependent on adopted expander exhaust valve timing, a peak power output of 4.7 kW could be achieved at expander intake temperature of 1073 K. System operating temperature for the optimal performance is also highly dependent on valve timings. Piston stroke length is adversely affected by an increase in compressor/expander diameter ratio and operating temperature. Peak system efficiencies of 40% and 60% could be achieved when the compressor/expander diameter ratio is 0.70 and 0.93, respectively.