Case Studies in Thermal Engineering (Oct 2023)
The thermal environment and thermal comfort of disaster relief tents in high-temperature composite environment
Abstract
To ensure the safety and comfort of personnel inside disaster relief tents, this study investigated the distribution of the thermal environment within the tents under composite conditions of high temperature and solar radiation. Furthermore, the interior environmental comfort was evaluated. An experimental platform for tent testing was developed, utilizing a wind tunnel coupled with multiple disaster scenarios and a thermal manikin system. The experiments were conducted under various conditions, including high temperatures and radiation levels of 300 W/m2, 600 W/m2, and 900 W/m2, as well as a wind speed of 1.2 m/s. Two scenarios were considered: doors and windows open or closed. The thermal environmental parameters inside the tent were measured, and the Comfort Prediction Model for Vehicles (CPMV) was employed to assess the thermal comfort of the interior environment. The results indicated a significant temperature rise inside the tent due to the radiation environment, with the maximum top surface temperature reaching 62 °C at 600 W/m2. Notably, a clear temperature stratification was observed among the three horizontal levels inside the tent. Opening the doors and windows resulted in a reduction of temperature below the 1.8 m level. However, when the external radiation intensity exceeded 600 W/m2, the cooling effect was minimal. The temperature stratification phenomenon inside the tent disappeared in the presence of wind, leading to an average temperature decrease of approximately 10 °C. The humidity inside the tent remained lower than the outside humidity. Owing to external irradiation, the black globe temperature inside the tent consistently exceeded the air temperature. The maximum heat flux occurred on the inner side of the tent near the top when the doors and windows were closed, reaching 250 W/m2, while the central heat flux remained relatively stable. When the external radiation during summer was around 300 W/m2, living inside the tent was within an acceptable range. As the radiation exceeded 600 W/m2, the overall thermal sensation became hot, and at 900 W/m2, the interior of the tent became excessively hot and intolerable. In such circumstances, it is recommended to regulate the duration of stay or implement cooling measures to prevent heat stress.
