Performance of a new tank design with variable outlet port in a thermosiphon solar water heating system

Abstract

A new tank design with variable outlets at different heights is lately proposed. In this paper, the new tank design is applied to a thermosiphon solar water heating system. The performance of the thermosiphon system is investigated for space heating of an office building. A mathematical model of the thermosiphon system is developed and validated against the experimental data. With the mathematical model, the system performance at weekend and weekday are simulated respectively. In the weekend situation, the new tank improves the stored thermal energy by 29.4% and reduces the system heat loss by 12%. In the weekday situation, the new tank improves the heat supply by 13.26 MJ and reduces the system heat loss by 5.6%. In addition, nocturnal reverse flow in the thermosiphon system is also investigated. The new tank succeeds in controlling the reverse flow by changing the exhausting height. The reverse flow in the new tank system is almost stagnant at night.