Comparative analysis of NIR point source and surface array probes in two-phase flow measurement model

As one of the most significant parameters, phase fraction is of great importance for ensuring the accuracy of two-phase flow measurement. Although near-infrared (NIR) technology has been widely used, its accuracy remains limited. Two methods have been proposed to reduce the energy loss of near-infrared light transmission signal in two-phase flow: the point light source method, which shortens optical path and the array light source method for increasing light source area. Experiments were conducted on single phase flow and gas–liquid two-phase flow, and the results indicated that the signal transmission effect of the point source near-infrared device was better. Using the experimental results from the point source near-infrared device, phase fraction models for bubble flow, annular flow, and slug flow were established. Validation results demonstrate that the relative measurement error of the three phase fraction models is within ± 4.96 %.