Numerical investigation of a two-phase CO2 ejector
Numerical investigation of a two-phase CO2 ejector
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DOI：
10.1016/j.ijrefrig.2014.03.003
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发表时间：
2014-07
期刊：
影响因子：
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通讯作者：
Christian Lucas;H. Rusche;A. Schroeder;J. Koehler
中科院分区：
文献类型：
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作者：
Christian Lucas;H. Rusche;A. Schroeder;J. Koehler
在蒸汽压缩制冷系统中使用喷射器作为附加部件是一种很有前途的提高系统效率的方法。制冷系统效率的提高很大程度上依赖于喷射器。利用CFD模拟，可以更好地了解两相CO2喷射器，从而设计出更高效的喷射器。本文采用基于齐次平衡法的数值模型，并在OpenFOAM中实现，对CO2引射器进行了数值模拟。对有吸力质量流和无吸力质量流的引射器进行了数值研究，并将数值结果与前人发表的实验数据进行了比较，以验证数值模拟的正确性。如果喷射器在没有吸力流动的情况下运行，则不会发生混合损失，而摩擦损失是影响流动的主要损失之一。因此，该工况适用于验证数值模型确定的摩擦损失是否正确。为了验证数值模型对混合损失的准确预测，对具有吸力流的引射器进行了数值模拟。在给出的数据范围内，数值模型对驱动质量通量的预测误差在10%以内。以10%的误差确定了无抽吸流工作的喷射器的压力恢复。当喷射器以吸气流量运行时，该误差增加到20%。
Using an ejector as an additional component in a vapor compression refrigeration system is a promising way to increase the system efficiency. The efficiency increase of the refrigeration system depends strongly on the ejector. Using CFD simulations, it is possible to obtain a better understanding of two-phase CO2ejectors in order to design more efficient ejectors. In this work, a numerical model based on a homogeneous equilibrium approach, which is implemented in OpenFOAM, is used to simulate the CO2ejector. The numerical investigation of an ejector operated with and without a suction mass flow is presented and the numerical results are compared to experimental data published in previous works to validate the simulations. If the ejector is operated without a suction flow, no mixing losses occur and the friction losses are one of the main losses affecting the flow. Thus, this operating condition is suitable to validate if the friction losses are determined correctly by the numerical model. Afterwards, an ejector which is operated with a suction flow is simulated in order to validate the accurate prediction of the mixing losses by the numerical model. In the presented data range, the numerical model predicts the driving mass flux within an error margin of 10%. The pressure recovery of the ejector operated without a suction flow is determined with an error of 10%. This error increases to 20% when the ejector is operated with a suction flow.