Numerical prediction of heat transfer characteristics based on monthly temperature gradient in algal open raceway ponds. (March 2017)

• Record Type: Journal Article
• Authors: Ali, Haider; Cheema, Taqi Ahmad; Park, Cheol Woo
• Is Part Of: International journal of heat and mass transfer. Volume 106(2017:Mar.)
• Page Start: 7
• Page End: 17
• Publication Date: 2017-03
• Subjects: Raceway pond -- Heat transfer -- Evaporation -- Turbulent mixing -- Aspect ratio; Heat -- Transmission -- Periodicals; Mass transfer -- Periodicals; Chaleur -- Transmission -- Périodiques; Transfert de masse -- Périodiques; Electronic journals; 621.4022
• DOI: 10.1016/j.ijheatmasstransfer.2016.10.061
• Languages: English
• ISSNs: 0017-9310

Abstract

Highlights: Heat transfer between pond water and atmosphere effects microalgae growth. Empirical relation is an effective approach in the design of microalgae raceway ponds. Optimal temperatures in raceway pond were achieved in the summer and spring. High paddle wheel rotational speeds reduced the thermal stratification. Heat loss in raceway ponds was increased by increasing the water depths. Abstract: This paper presents a novel empirical correlation to estimate the heat transfer in raceway ponds for different pond sizes and depths. The correlation involves the calculation of Nusselt number. Heat transfer in outdoor raceway ponds was modeled with the effects of pond design, hydrodynamics, and environmental conditions. Monthly average water temperature, Nusselt number, and Prandtl number were used to examine the heat transfer phenomena between pond and its surroundings. A novel relation was also employed to estimate the amount of monthly evaporated water from the raceway ponds. Different aspect ratios, pond depths, and paddle wheel rotational speeds were considered to evaluate the effect of pond geometry and turbulent mixing on heat transfer. The use of empirical relation is an effective approach in designing raceway ponds to estimate heat loss in ponds. Algal productivity decreased with increasing amount of evaporated water. Moreover, the environmental conditions, pond design, and turbulent mixing significantly affected the heat transfer rate and the optimum water temperature for algal growth.