With respect to solar energy utilization of buildings

a solution chemical energy storage mode is proposed based on membrane distillation technology focusing on the low density of solar radiation distribution and the imbalance between energy supply and demand

the purpose of which is to convert solar energy into solution chemical energy. A hydrophobic polyvinylidene fluoride (PVDF) hollow fiber membrane with operational characteristics of a normal temperature region and low temperature difference is adopted as the membrane material

and the PVDF membrane material has a highly specific surface area microscopically and a huge contact area per unit volume; as a result

a lithium bromide solution can be concentrated and stored using the vacuum membrane distillation mode

and the concentrated solution can be used as the working medium of the absorption thermal system. Therefore

experimental tests of the vacuum membrane distillation of a lithium bromide solution were carried out under different operating temperatures

solution flow rates

and vacuum degrees. According to the experimental results

a solar-driven solution energy storage system based on membrane distillation is described. The results show that the energy storage intensity can reach 245 kJ/kg

and the hollow fiber module can produce 0.27-0.40 kW of energy storage per square meter. Thus

membrane distillation solution storage provides a new approach to absorption thermodynamic systems and storage technology.