Experimental investigation on the internal working process of a CO2 rotary vane expander
Experimental investigation on the internal working process of a CO2 rotary vane expander
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CO2旋片式膨胀机内部工作过程实验研究
DOI：
10.1016/j.applthermaleng.2008.11.023
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发表时间：
2009-08
影响因子：
6.4
通讯作者：
彭学院
中科院分区：
文献类型：
--
作者：
彭学院
为提高跨临界CO2制冷循环的性能系数(COP)，研制了替代节流阀的旋叶式膨胀机样机，对其内部工作过程进行了实验研究。通过设置在膨胀室内的两个压力传感器记录了压力随旋转角度的变化图(p-θ图)，并在此基础上分析了工作过程的特点，讨论了一些改进措施对内部泄漏的影响。与理想的p-θ图相比，记录的图显示了膨胀机膨胀过程中压力的快速下降，这是由于膨胀机内部严重泄漏所致。对记录的p-θ图的进一步分析表明，三个相邻的叶片而不是两个形成了一个完整的工作室，这意味着中间的叶片根本没有接触到气缸壁，这一猜测得到了CO2系统膨胀机运转过程中转子和叶片的高速录像的证实。通过在叶片槽内设置弹簧，保证了叶片与气缸壁的紧密接触，从而改进了工作工艺。吸口和排气口之间的间隙是另一个重要的泄漏通道，安装密封可以减少从高压吸气室到低压排气室的直接泄漏，从而使通过膨胀机的压差增加1.5-2.5 Mpa。对改进后的膨胀机样机进行了性能测试，结果表明，在800rpm转速下，膨胀机的容积效率由17%提高到30%，等熵效率由9%提高到23%。
This paper presents the experimental investigation on the internal working process especially the internal leakage of a rotary vane expander prototype, which was developed to replace the throttling valve to improve the Coefficient of Performance (COP) of the transcritical CO2refrigeration cycle. The pressure diagram as a function of the rotation angle (p–θ diagram) was recorded by two pressure sensors arranged within the expansion chamber, based on which the features of the working process were analyzed and effects of the some improvement measures on the internal leakage were discussed. Compared with the ideal p–θ diagram, the recorded diagrams presented more rapid decrease in the pressure during expansion process, which was attributed to serious leakage within the expander. Further analysis of the recorded p–θ diagrams showed that three adjacent vanes instead of two formed an integrated working chamber, which implied that the in-between vane did not contact the cylinder wall at all, and this guess was proved by the high speed video recording of the running rotor together with the vanes during operation of the expander in CO2system. By arranging springs in the vane slots, tight contact between the vanes and the cylinder wall was ensured and hereby the working process was improved. The gap between the suction and discharge ports was another important leakage path and installation of a seal there could increase the pressure difference through the expander by 1.5–2.5MPa by decreasing the leakage directly from the high-pressure suction chamber to the low-pressure discharge chamber. Performance test of the modified expander prototype with springs in the slots and seal at the seal arc showed that the volumetric efficiency increased from 17% to 30% and the isentropic efficiency from 9% to 23% at the speed of 800rpm.
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影响因子：
11.2
作者：
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通讯作者：
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影响因子：
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作者：
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影响因子：
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通讯作者：
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DOI：
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发表时间：
2006
期刊：
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影响因子：
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通讯作者：
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DOI：
--
发表时间：
2006
期刊：
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影响因子：
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作者：
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通讯作者：
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