Analysis of Low-Altitude Inversion Characteristics of Coal-Fired Power Projects Based on Tethered Balloon Observation

Abstract

Atmospheric inversion phenomenon directly affects the vertical movement of air, which causes the cooling heat of the cooling tower in the power plant to be blocked. Therefore, it is necessary to analyze the atmospheric inversion characteristics of the research project during the design of the air cooling system. Using the low-altitude observing system of the tethered balloon, the on-site observation of the temperature below 300 m in summer is carried out for a coal-fired power integration project in Yulin, Shaanxi, China. Observations were made at 10 fixed times per day, with a cumulative observation of 46 days and 247 effective detections. The data were quality-controlled, and then linearly interpolated. According to the requirements of the project designer, the temperature data of 20, 50, 100, 150, 200, 250, 300 m was used for low-temperature inversion analysis. The research shows that the grounding inversion and low-altitude inversion can be observed at the same time. In the time and space changes, the grounding inversion temperature and intensity are significantly higher than the low-altitude inversion. The maximum inversion of grounding inversion and low-altitude inversion is 2.3?C/hm, 1.0?C/hm. Grounding inversion temperature occurs every time, the frequency is the highest at 20 o’clock, the average intensity is maximum at 17 o’clock, and the average height, maximum intensity and maximum height are maximum at 7 o’clock. When the low-altitude inversion temperature is 18 o’clock, other times can occur, and the frequency is the highest at 15 o’clock, but the inversion layer is shallow, the bottom is high and the intensity is small. Grounding inversion and low-altitude inversion can occur in all levels, and as the height increases, the grounding inversion decreases and the low-temperature inversion increases. The design of the project air cooling tower needs to fully consider the impact caused by the inverse temperature below 300 m.