Performance study of enhanced and smooth surface tubes in a system condenser of a multistage flash desalination unit

Fouling of the multistage flash (MSF) system condenser tubes used for water desalination reduces the system overall heat transfer coefficient very rap idly. Consequently, hearts the system efficiency and increases the cost of distillate water. In this study, a comparison between enhanced and plain tu be performance characteristics is investigated experimentally in the MSF sy stem. The study is performed for aluminium-brass tubes with inside diameter s of 19.05, 23, and 29.5 mm. A three different flow velocity of 0.1, 0.1645 , and 0.2398 mrs are examined with these three tubes. The study is carried over for two different coolants fresh and brine water. In this paper, the r esults for fresh water are presented. The results indicated that the overal l heat transfer coefficient (Li? varies with both coolant flow velocity and tube diameter. For both smooth and enhanced tubes, the higher the coolant speed or/and pipe diameter the larger the overall heat transfer coefficient . However, the effect of these two parameters is more significant with enha nced tubes. A gain in overall heat transfer coefficient by factor of 2.13 o ver smooth tubes can be achieved. Results also, showed that for certain tub e diameter there is an optimum flow speed for maximum value of U. For a cer tain flow speed there is an optimum pipe diameter size. The results proved that the heat transfer coefficients of corrugated tubes are superior to pla in tubes for most flow speeds and diameters investigated in the present stu dy.