Study On Fabrication Technology, Performances And Melting Heat Transfer Process Of Salt/Ceramic Composite Energy Storage Material

Heat energy storage technique can solve the inconsistency of energy supply and demand, improve utilization efficiency of energy and conserve environment. Phase change materials (PCMs) and sensible heat materials applied in the heat energy storage technique have some fatal disadvantages. The heat transfer effect of PCMs is very bad on the interface of solid and liquid, the chemical stability is very low, and it will erode the container. The heat storage density of sensible heat materials is very low, the process of energy storaging or releasing is very difficult to be controlled, and type of sensible heat materials is very limited to be selected. So it is the focus and difficulty to develop a new type of composite energy storage material what can integrate advantages of PCMs and sensible heat material and get rid of their disadvantages.An innovating technology is put forward in this paper and the new type salt /ceramic composite energy storage material (CESM) is fabricated successfully by mixing and sintering method. The CESM can solve problems of existing PCMs and sensible heat materials, and exchange heat in direct contact with compatible fluid in the process of energy storage, so the efficiency of exchanging heat is improved greatly.Sodium sulfate has bigger latent heat and specific heat, and lower vapor tension. Silicon dioxide has better thermal stability feature and high heat conductivity coefficient. And the chemical compatibility of them is very good. So sodium sulfate is selected as PCM and silicon dioxide as carrier material. The fabrication technology of salt/ceramic CESM is researched and the effect of the technology parameters including raw material percentage, forming pressure, sintering temperature, heat preservation time and binder percentage to structure and mechanical performances and microstructure is discussed. And the optimum technology conditions of fabricating Na₂SO₄/SiO₂ CESM are obtained. The components and microstructure of Na₂SO₄/SiO₂ CESM are researched in detail by XRD, SEM and POL.. The XRD results show no new substance appears other than sodium sulfate and silicon dioxide. The SEM and...