Production Analysis of a Tubular Solar Still

Abstract

In this study, attempts were made to provide a group of complete heat and mass transfer correlations, and to propose a new heat and mass transfer model for a Tubular Solar Still (TSS) by taking account of thermal properties of the humid air inside the still. We developed a new experimental technique for directly measuring the evaporation rate from the saline water surface in the TSS and evaluated the evaporative mass transfer coefficient. Indoor experiments were conducted to investigate the production performance and the heat and mass transfer coefficients of the TSS. It was found that i) the heat and mass transfer coefficients, h cha , h cw , h cdha , h ew can be expressed as functions of the temperature difference between the saline water and the cover, and ii) the conventional formula available for a basin type still overestimates the convective heat transfer coefficient, h cw for the TSS. Furthermore, in this study, the long-wave radiation interaction between the water surface and the tubular cover was shown theoretically.We also proposed a new heat and mass transfer model of TSS. The mass balance of water vapor inside the still was formulized for the first time. The proposed model was successful in the calculation of humid air properties (temperature, vapor density and relative humidity) and condensation flux on the tubular cover inner surface besides the saline water temperature, tubular cover temperature, trough temperature and evaporation flux. The validity of the model was evaluated from the comparison with field experiments in Fukui, Japan and in Hamuraniyah, UAE. It was seen that the calculated results also had a good agreement with the field data.

Estimation of convective heat transfer coefficient and water-productivity in a tubular solar still – CFD simulation and theoretical analysis

“…7 shows the results of mass productivity calculated by Eq. (24) and experimental data reported by Islam and Fukuhara (2007). The results show that Eq.…”

“…Fig. 4 compares mass productivity calculated by CFD analysis with experimental data reported by Islam and Fukuhara (2007). The results show that CFD simulation can predict mass productivity within the range of 15%.…”

“…3 shows the plot of grid dependency check for the tubular solar still. Furthermore, in order to validate the numerical analysis, the solution obtained has been compared with the experimental data for a given geometry reported by Islam and Fukuhara (2007). Table 1 shows the geometry used in validation of CFD simulation.…”

Computational fluid dynamic as a tool for solar still performance analysis and design development: a review

“…Quantitatively comparison The results of water productivity and water temperature of the present study were similar to experimental results. Rahbar et al [53] and Bafghi et al [54] Verification Quantitatively comparison The water productivity obtained from numerical solution has been compared with the experimental data for a given geometry reported by Islam and Fukuhara [71]. The results show that CFD simulation can predict mass productivity within the range of 15%.…”

Evaporation Phenomenon Inside a Solar Still: From Water Surface to Humid Air

“…The second model of the TSS was, therefore, designed to meet these requirements and to improve some of the limitations of the basin-type still and of the TSS made of glass. Since the cover material (a vinyl chloride sheet) is a little heavy and cannot form into an ideal size easily Fukuhara & Islam, 2006;Islam et al, 2005;Islam et al, 2007a), a polythene film was adopted as a cheap new material for the cover. Consequently, the cover weight and the cost of the second model were noticeably reduced and the durability was distinctly increased.…”