Study on improvements of airplane pre-conditioning air unit in Xining Airport

 Airplane pre-conditioning air unit (PCA) has a history of nearly 10 years in China. But the temperature difference of outdoor air handled by PCA is as high as 30 to 40 ℃, and the energy efficiency ratio of the unit is usually less than 2. High energy efficiency, portability and stability are the development trend of PCA in the future. Combined with the climate characteristics of Xining area and the design characteristics of cold and heat sources of the terminal, this paper makes an improvement on the basis of conventional units. It is put forward that the first-stage pre cooling is adopted in summer, and the pre cooling water temperature is 16 ℃. The second stage adopts deep compression refrigeration, and water cooling is used for condensation. The third stage adopts the technical scheme of air cooling to ensure the cooling in the transition season. According to the heating forms in winter, it is further divided into scheme 1 (electric heating), scheme 2 (central heat source preheating) and scheme 3 (preheating and precooling shared surface cooler). The results show that the investment and operation costs of scheme 1 are lower than those of conventional units. The investment of scheme 2 and scheme 3 is higher than that of conventional units. But in terms of long-term operation, they are much better than that of conventional units. Compared with conventional units, the operating carbon emissions of the three schemes are reduced by 1.9, 2.8, 3.3 kt/a, respectively.