Numerical study of heat transfer by convection and thermal radiation in a ventilated room with human heat generation and co2 production

摘要

The purpose of this work is to study the combined effect of heat generation produced by a human being and the mixed turbulent convection with thermal radiation, as well as the COsub2/sub production from respiration. These factors are important to achieve healthy and pleasant indoor comfort conditions and to optimize the energy use in buildings. Numerical results in a rectangular ventilated room (3.0 m x 2.5 m) were carried out considering temperatures on the vertical walls of 298 and 308 K (25 and 35 °C) and the remaining walls were considered as adiabatic. The temperature surface of the human being was maintained at 307 K (34 °C). The inlet velocities were 0.05 m/s and 0.5 m/s, whereas the assumed emissivity values of the walls were 0.0 and 0.8. The mathematical model was solved numerically with software of Computational Fluid Dynamics. The flow patterns (streamlines), the temperature fields (isotherms) and COsub2/sub concentration distributions are presented and discussed. Besides the heat transfer coefficients are reported. The results show that the natural ventilation reduces the average temperatures in the room between 4°C and 5.5°C, while the thermal radiation increases the average temperature between 0.2°C and 0.4°C.