Self-Insulating Passive Solar Heating System Using a Heat Pipe and Phase-Change Material. Final Report, September 30, 1979-September 30, 1981

摘要

In this work a combination of heat pipes and thermal-storage-phase-change material was employed to provide an improved, lightweight, window-mounted, solar, heating system having a high efficiency in collecting available solar energy, reduced heat losses to the outdoors, and thermal storage for up to several days. To provide quantitative comparisons of the new system with conventional passive thermal storage walls, the new system and a conventional one were built and installed in adjacent identical windows. Testing was done from February to April 1981. The results obtained showed that this new design provides three significant advantages over conventional passive thermal storage walls in which the packaged thermal storage material is exposed directly to sunlight in a window. The first advantage is that it nearly totally eliminates heat losses from storage. Heat loss from storage is reduced to the loss through the insulation surrounding the storage chamber. The second advantage is permitting thermal storage for several days instead of the few hours possible with the conventional storage walls even with triple glazing or some sort of insertable insulation. In one run thermal energy was stored from Friday to Monday evening in the new system. The third significant advantage is a substantial increase in the efficiency, i.e., the percentage of incident solar energy which can be delivered to the room after sunset. The average efficiency of the heat-pipe unit for fourteen runs was 47.8% while the average efficiency of the conventional unit for the same fourteen runs was only 34.4%. (ERA citation 10:022573)