EXPERIMENTAL STUDY OF HEAT EXCHANGE DURING FORCED WATER FLOW IN A VERTICAL STEAM GENERATING CHANNEL

Measurements of heat transfer during boiling water in a vertical heated pipe with a diameter of 13 mm and a length of 2.6 m were carried out. The studies were carried out in the range of pressure changes from 4 MPa to 16 MPa, mass velocity from 120 kg/m2s to 2000 kg/m2s, heat flow from 0.13 MW/m2 to 2.59 MW/m2. The region of developed boiling was studied in the range of changes in vapor content from 0 ≤ x ≤ 1. Experimental results show that mass velocity does not have a significant effect on the heat transfer coefficient. With increasing pressure, the heat transfer coefficient increases. An equation has been obtained that describes the dependence of the heat transfer coefficient on the flow parameters and heating intensity. It is shown that in the region 0 ≤ x ≤ 1 the heat transfer coefficient smoothly decreases with increasing vapor content. An increase in the heat transfer coefficient before the heat transfer crisis is observed in some modes at high values ​​of steam content. Qualitatively, this result is consistent with the experimental results [7] and is explained by an increase in the convective component of the boiling process in the dispersed ring mode when the near-wall liquid film is depleted.