Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
A simplified combined displacement and personalized ventilation model
A multi-layer model has been developed to represent thermal transport in rooms equipped with combined displacement ventilation and personalized ventilation systems. The air movements and temperatures in the plumes and the rest of the room are represented separately at each air layer in a room of seven layers. The personalized ventilation is included in the layer containing the trunk and head of the human body and is considered to affect the heat source plume temperature and flow rate. The temperatures and flow rates of the plumes and the surrounding air at each layer are calculated by solving the heat and mass balance equations. The multi-layer model results were compared with results obtained from experimental measurements. Eight experimental cases were considered for the validation of the model at a displacement ventilation flow rate of 60 L/s (127 ft3/min) and temperatures of 18°C and 20°C (64.4°F and 68°F) along with personalized ventilation flow rates of 4 L/s and 7 L/s (8.47 ft3/min and 14.83 ft3/min) and temperatures of 20°C and 22°C (68°F and 71.6°F). Measurements of the surrounding air temperature and the heat source plume centerline temperature were taken and compared to the predicted results of the model. The simplified model accurately predicted the surrounding air temperature at the higher levels, while it lightly underestimated by 6% the lower level temperatures. At lower personalized ventilation flow rates and temperatures, the model was able to predict accurately the plume temperature directly above the human, but it underestimated the plume temperature when it gets closer to the ceiling or when the personalized ventilation flow rate and temperature are increased.
A simplified combined displacement and personalized ventilation model
A multi-layer model has been developed to represent thermal transport in rooms equipped with combined displacement ventilation and personalized ventilation systems. The air movements and temperatures in the plumes and the rest of the room are represented separately at each air layer in a room of seven layers. The personalized ventilation is included in the layer containing the trunk and head of the human body and is considered to affect the heat source plume temperature and flow rate. The temperatures and flow rates of the plumes and the surrounding air at each layer are calculated by solving the heat and mass balance equations. The multi-layer model results were compared with results obtained from experimental measurements. Eight experimental cases were considered for the validation of the model at a displacement ventilation flow rate of 60 L/s (127 ft3/min) and temperatures of 18°C and 20°C (64.4°F and 68°F) along with personalized ventilation flow rates of 4 L/s and 7 L/s (8.47 ft3/min and 14.83 ft3/min) and temperatures of 20°C and 22°C (68°F and 71.6°F). Measurements of the surrounding air temperature and the heat source plume centerline temperature were taken and compared to the predicted results of the model. The simplified model accurately predicted the surrounding air temperature at the higher levels, while it lightly underestimated by 6% the lower level temperatures. At lower personalized ventilation flow rates and temperatures, the model was able to predict accurately the plume temperature directly above the human, but it underestimated the plume temperature when it gets closer to the ceiling or when the personalized ventilation flow rate and temperature are increased.
A simplified combined displacement and personalized ventilation model
Alain, Makhoul (Autor:in) / Kamel, Ghali (Autor:in) / Nesreen, Ghaddar (Autor:in)
HVAC&R Research ; 18 ; 737-749
01.08.2012
13 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Unbekannt
VALIDATION OF DISPLACEMENT VENTILATION SIMPLIFIED MODELS
| British Library Conference Proceedings | 1997