| 摘要 |
A solar heater has a tubular copper pipe deformed along one longitudinal line to form two concentric semi-tubular walls (12, 14) spaced-apart by a distance of 4mm. The radially inner wall (12) is concave in cross-section and this provides a greater surface area for transferring energy from the solar radiation to the fluid within the pipe. Since the walls (12, 14) are closely spaced, the pipe contains only a small amount of water which therefore may be heated to a higher temperature than in existing heaters. The pipe is embedded in an elongate block (16) of insulating foam, and the foam and the pipe are both enclosed in a plastics film (34) to increase the absorption of energy from the solar radiation. <IMAGE> |
