Two-phase flow, pressure drop, and Joule-Thomson coefficient (JT_h) of sub- and super- critical carbon dioxide expanding through a 81 µm orifice embedded inside a 300 µm microchannel was experimentally studied. It was demonstrated and validated that a flow of CO₂ in a micro-orifice can support the thermodynamic conditions that are ripe for the JT_h effect to be significant. The inlet pressure, temperature, and mass flux were independently varied between 5.6 MPa and 10.2 MPa, 293 K and 314 K, and 47,277 kg/m²s and 162,101 kg/m²s, respectively. The measured pressure drop and Joule-Thomson coefficient ranged from 0.1 MPa to 5 MPa and from 0 K/MPa to 10 K/MPa, respectively. Pressure drop results were compared with the homogenous two-phase flow model, the separated two-phase flow model, the capillary tube model, and an empirical fit equation that resulted in mean average errors of 0.84 MPa, 1.4 MPa, 0.7 MPa, and 0.75 MPa, respectively.

实验研究了通过嵌入 300 µm 微通道内的 81 µm 孔口膨胀的亚临界和超临界二氧化碳的两相流、压降和焦耳-汤姆逊系数 ( JT _{h )。}已经证明和验证，微孔中的 CO _{2流动可以支持使}JT _h效应显着的成熟的热力学条件。入口压力、温度和质量通量在 5.6 MPa 和 10.2 MPa、293 K 和 314 K、47,277 kg/m ² s 和 162,101 kg/m ^{2之间独立变化}s，分别。测得的压降和焦耳-汤姆逊系数分别为 0.1 MPa 至 5 MPa 和 0 K/MPa 至 10 K/MPa。将压降结果与均质两相流模型、分离两相流模型、毛细管模型和经验拟合方程进行比较，得出的平均误差分别为 0.84 MPa、1.4 MPa、0.7 MPa 和 0.75兆帕，分别。