Experimental studies on heat transfer and friction factor characteristics of parabolic trough solar water heating system with and without twisted tapes

摘要

Experimental investigation of heat transfer and friction factor characteristics of solar parabolic trough collector fitted with full length twisted tapes inserts of twist ratio 6, 8 and 10 have been presented. The transitional flow regime is selected for this study with the Reynolds number range 1192 to 2534. The experimental data obtained were compared with those obtained from plain tube published data. The effects of full length twisted tape inserts on heat transfer and friction factor were presented. The heat transfer coefficient enhancement for twisted inserts is higher than that for plain tube for a given Reynolds number. The use of twisted inserts improved the performance of solar trough collector.