Experimental and theoretical study on density wave instability in low quality natural circulation loop

Unlike the situation of high quality two phase flow stability research, the investigation for low quality two phase flow stability is far from thoroughness. With the development of integral type natural circulation heating reactor, low quality two phase flow stability investigation has been paid more attention in over last ten years in China. A series of thermal-hydraulic experimental research has been carried out at INET on two full-scale test loops which respectively simulated two prototype heating reactors in important geometrical and operational parameters. In order to supply test data, choose suitable models for design and safety analysis of heating reactor, and extend the present stability investigation results of high quality region into low quality region, the further theoretical and experimental research is necessary. Part of the experimental research results from the thermal-hydraulic test loop HRTL-200 of the heating reactor NHP200. the main idea of a computer code based on the homogeneous flow linear stability analysis model, and analysis results from the code are presented in this paper With regard to steady-state flow rate and low quality two phase flow instability, the comparison between the experiment results and numerical results shown that the homogeneous equilibrium two phase flow model could distinguish and predict low quality and high quality density-wave oscillation regions, and the agreement between the analysis and experimental result was satisfactory.