| 초록 |
In this study, a total of 1,322 high pressure (70≤P≤200bar) and high mass flux (2003≤G≤10,587㎏/㎡s) data points of CHF(critical heat flux) in uniformly heated vertical round tubes for water were collected 6 different sources from world literature. This data consisited of following parameter ranges: 1.91≤D(diameter)≤12.80㎜, 0.04≤L(length)≤4.97m, 0.48≤qc(CHF)≤19.16MW/㎡ and -0.82≤X(exit quality)≤0.81. The new CHF correlation comprises local variable, namely, the "true" mass quality, mass flux, tube diameter, and two parameters that are a function of pressure only. This study reveals that by incorporating the true mass quality into the local condition hypothesis, the prediction of CHF under these condition can be obtained accurately, while overcoming the difficulties of flow instability and buoyancy effects. The new correlation predicts the CHF data significantly better than do the currently available correlations, within root-mean-square errors of 12.22%, obtained by the heat balance method. |
