Chugging Test with DN100 Blowdown Pipe in the PPOOLEX Facility
Markku Puustinen, Jani Laine, Antti Räsänen, Elina Hujala,
This report summarizes the results of the DCC-05 direct contact condensation experiment in 2013 with the scaled down PPOOLEX test facility designed and constructed at Lappeenranta University of Technology. The main purpose of the DCC-05 experiment was to obtain high quality measurement data from the chugging condensation mode for the validation of DCC models used in CFD codes and to make 3D high speed video recordings to be used in the development work of pattern recognition algorithms. During the experiment the DN100 blowdown pipe was equipped with extra temperature measurements for capturing different aspects of the investigated phenomena.
The general trend of the measured parameters in the DCC-05 experiment was similar with those of the corresponding chugging experiments carried out with the DN200 blowdown pipe. Temperatures in the gas space of the wetwell rose due to compression by pressure build-up. As the gas space temperatures increased, they also stratified. During the DCC-05 experiment the pool water stratified, too. Temperatures at the pool bottom remained close to the initial value but increased from the blowdown pipe outlet elevation upwards so that water was warmest on the pool surface.
During the chugging mode high pressure loads were measured inside the blowdown pipe and at the pool bottom. However, the oscillating movement of the steam/water-interface inside the blowdown pipe during the chugging periods was not very wide. The interface reached the elevations of 200 mm (TC05) and 260 mm (TC06) above the pipe outlet few times. In the previous experiments with the DN200 blowdown pipe the up and down movement of the steam/water-interface has been much larger.
The high frequency measurement data of the DCC-05 experiment in PPOOLEX can be used in the validation of DCC models of CFD codes. Furthermore, the pattern recognition algorithms being developed and improved at LUT can be later used to assess the steam bubble surface area and volume as well as the chugging frequencies from the video material as a function of pool water temperature and steam mass flux.