Local Phenomena of Heat Transfer Near the Pseudo-critical Point of Carbon Dioxide
For reactors cooled and moderated by supercritical water, an exact knowledge of the heat transfer mechanism is required to avoid wall overheat and possible damages. The fluid properties of water at supercritical pressures are significantly temperature dependented. Thus, heat transfer correlations are usually not accurated in the region around the pseudo-critical point where the properties have the strongest gradients. Near the pseudo-critical point deterioration of heat transfer might happen which is not fully understood yet. Therefore, experiments with simple geometry and high spatial resolution are required. As known from previous experiments heat transfer phenomena in supercritical water and supercritical carbone dioxide are similar. To investigate heat transfer phenomena in supercritical carbon dioxide, velocity and temperature profiles in the boundary layer of a wire heated channel are to be locally determined. For this reason an optical access is mandatory. Lens and camera have to be able to resolve the layer near the wall up to a characteristic wall coordinate of y+≈0.1. Well-defined inlet and boundary conditions are required to reproduce experiments by means of CFD-calculations. The experimental loop, the test section with optical access, instrumentation and measuring methods to examine the phenomena in the boundary layer are described in this paper. First results of scoping experiments are presented.
Carmen Isabella Krau Dietmar Kuhn Thomas Schulenberg
Karlsruhe Institute of Technology Institute for Nuclear and Energy Technologies 76131 Karlsruhe Germany
国际会议
上海
英文
378-387
2010-10-10（万方平台首次上网日期，不代表论文的发表时间）