Different from conventional vapor compression heat pump system, this investigation presented a semi-open air cycle heat pump system, whose performance was experimentally assessed across diverse conditions. The prototype showcased stable heating performance with coefficient of performance surpassing 1.0 at ambient temperatures above −7°C and maintaining its variation within 15 % in the ambient temperature range of (−30 ∼ 7) °C. According to the analysis of the experimental results, although frosting has an impact on some parameters, the overall efficiency of the system remains stable over time. These special designs of high-pressure ratio and oil cooling of compressor could make the system temperature reaching 132 °C, indicating that the system has the potential for application in the field of high temperature heating. Heat exchanger analysis revealed an imbalance in heat exchange ratios between oil–water heat exchanger and air–water heat exchanger. The prototype achieved 58 ∼ 72 % of a significant conversion efficiency of electric energy to oil internal energy, proposing that utilizing high compression efficiency compressors could enhance system coefficient of performance by (13.47 ∼ 31.50)%. The isentropic efficiency and expansion work recovery efficiency of booster turbo-expander were calculated as (59 ∼ 65)% and (33 ∼ 40)% respectively. Additionally, it was found that frosting could optimize the recovery rate of expansion work under specific conditions.

中文翻译：

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增压透平膨胀机半开放式空气循环热泵系统实验研究


与传统的蒸汽压缩热泵系统不同，本研究提出了一种半开放式空气循环热泵系统，其性能在不同的条件下进行了实验评估。该原型机表现出稳定的加热性能，在-7°C以上的环境温度下性能系数超过1.0，在(-30 ∼ 7)°C的环境温度范围内其变化保持在15%以内。根据实验结果分析，虽然结霜对部分参数有影响，但随着时间的推移，系统的整体效率保持稳定。这些高压比和压缩机油冷却的特殊设计可以使系统温度达到132℃，表明该系统具有在高温加热领域的应用潜力。换热器分析表明油-水换热器和空气-水换热器之间的换热比不平衡。该样机实现了 58 ∼ 72 % 的电能到油内能的显着转换效率，表明采用高压缩效率压缩机可以将系统性能系数提高 (13.47 ∼ 31.50)%。计算得出增压透平膨胀机的等熵效率为（59～65）%，膨胀功回收效率为（33～40）%。此外，还发现结霜可以优化特定条件下膨胀功的恢复率。