THERMAL PERFORMANCE STUDIES AND ENERGY CONSERVATION POTENTIAL OF AN EARTH-AIR-PIPE SYSTEM COMBINED WITH DESICCANT COOLING

摘要

An earth-air-pipe system combined with desiccant cooling was constructed using soil as heat sink for space cooing in a primary school in South China. Thermodynamic analysis was made on different outdoor air conditions for comparison of the performances of earth-air-pipe system with or without desiccant cooling. Experiments were also carried out in the primary school, and the performance and cooling potential were estimated on the earth-air-pipe system combined with desiccant cooling. The experimental results indicated that individual earth-air-pipe system worked well with 25.1℃ at outlet and cooling potential of 4.2 kW was supplied in the climates where it was not hot. In hot and humid climates the outlet temperature of the earth-air-pipe averaged about 27.2℃ and a desiccant cooling cycle needed to be coupled after earth-air-pipe outlet to dehumidify and cool air further. The desiccant cooling could provide extra 2.1 kW cooling potential besides 2.9 kW of earth-air-pipe system. The thermal performance and cooling potential of earth-pipe system combined with desiccant cooling were greatly improved compared with individual earth-to-air heat exchangers. It is concluded that good thermal comfort can be obtained reasonably for space cooling with such an earth-air-pipe system combined with desiccant cooling.