An Experimental Investigation of the Influence of the Humidity Supply Tuyere Shape on the Indoor Temperature and Humidity Fields Under Low Pressure Drying Conditions

Abstract

Due to the low pressure and cold conditions of the Tibet Plateau in China, the indoor environment is extremely dry during the heating period in winter, seriously affecting the health of indoor personnel. Low-pressure conditions lead to significant variations in the air physical properties along with the diffusion process of wet components from those in the plain. Therefore, it is extremely important to develop an indoor air humidification strategy suitable for the plateau buildings. In this regard, the moisture supply air outlet shape is one of the key factors affecting the distribution of the indoor humidity field. In this paper, the effects of five types of humid air outlets （spherical, open angle, parallel slit type, circular slit type, and round tube nozzle outlets）on the diffusion characteristics of the indoor wet components and the indoor temperature and humidity fields of plateau buildings are studied using experiments. The results showed that the shape of the humid air outlet has a great influence on the indoor temperature and humidity distribution in the building. The wet environment creation ability of the spherical humid air outlet is found to be the weakest. In this regard, the humidity range it can create is only around 1/3 of that of other air outlets. Also, the humidity field uniformity of the parallel slit type humid air outlet is the best, leading to an indoor relative humidity of more than 80% within 20 minutes. It was also shown that the circular pipe spout reduces the internal effective moisture outlet area and can reduce the humidity field range by 1 to 2 square meters along the longitudinal direction. The research results obtained in this study provide a reference for the optimization of the form design of precise chemical delivery wet ports.

Keywords: Low-pressure area, Extreme dryness, Indoor wet environment, Moisture supply air outlet, Humidity field.