A new design of a solar water storage wall: a system-level model and simulation

Abstract

Some configurations have been proposed as passive solar wall, but nearly all of them suffer from common shortcomings such as high heat loss flux and low thermal capacity. In this paper, a modified design for building passive solar wall is proposed and a detailed computerized model for its dynamic behavior was developed as a triplet (S, Q, M) from first principles and empirical equations, such that the designer is able to alter any of the variables. Hence, the wall-room properties can be adjusted to improve the wall performance. In this model, S is a solar water wall which is designed on the south wall of a building with a water storage tank as the sensible thermal storage placed inside to passively heats the space with controlled heat transfer and a sufficiently sized storage. Also, Q is a question relating to S which is the performance evaluation of the proposed system including annual and monthly performance along with the room and storage temperatures. Finally, M is a set of mathematical statements $$\hbox {M}=\left\{ {\Sigma \_\hbox {1},\Sigma \_\hbox {2},\Sigma \_\hbox {3},\ldots } \right\} $$ which can be used to answer Q. The statements M are based on the lumped capacitance approach which utilizes solar optocalorics, solar thermal conversion and convective heat transfer to simulate passive space heating of a small building. A code was developed to solve the problem and to evaluate parametric sensitivity for design features. A new TrnSys model was introduced and the code results were compared with TrnSys outcome.