Abstract: The influences of thermophysical properties of an enclosure on the energy consumption of an active ventilated thermal control system and the thermal control effects, such as time stability and space uniformity of the object surface temperature, under periodic environmental conditions are investigated. The effects of the thermal conductivity and volumetric heat capacity of enclosure on the average power consumption of system and the thermal control effects of object are studied based on a simplified model under the actual weather conditions. It is discovered that the influence of the volumetric heat capacity depends on the value of the thermal conductivity, the inlet air temperature as well as the average temperature of ambient air. When the average ambient air temperature is higher or lower than the inlet air temperature, the thermal conductivity becomes a dominant factor. However, when the average ambient air temperature is close to that of the inlet air, the volumetric heat capacity has little effect on the average power consumption and the thermal control effects if the thermal conductivity is less than 0.1 W/(m·K); if the thermal conductivity is higher than 0.1 W/(m·K), the increase in the volumetric heat capacity could not only reduce the average power consumption but also enhance the time stability and the space uniformity of the object surface temperature as well.

Key words: engineering thermophysics, periodic environmental condition, thermal conductivity, volumetric heat capacity, thermal control effects, average power consumption