Study On Preparation Of Granulated PCM And Performance Of A Novel Heat Pipe Style Latent Heat Storage Unit For High Temperature Utilization

In this paper, a low-cost and mass-produced granular compositephase change material (PCM) for high temperature utilization isdeveloped. The melting intercalation is used to prepare this newcomposite PCM. Mixed nitrate, a PCM, is intercalated thenano-interlamination of the Na-bentonite and mixed nitrate/Na-bentonitephase change composite material has been prepared．The effect factorsand experimental conditions on the basis of experiment data are discussedin this paper．Some primary instruments, such as DSC,SEM,SDD EDS,and SDT, are used to guide research on phase change materials．Resultsreveal that granular composite PCM prepared has many strong points,such as preferable stability and no leakage when PCMs melt and freeze.A novel heat storager containing porous phase change materialabove-mentioned of heat pipe type is also presented. Instead of referringto the process of PCM undergoing when store or release heat, the conceptof phase change in the designed heat storager particularly underlines the heat transfer pattern that heat transfer fluid (HTF) undergoes between thePCM and the heat/cold source. This heat transfer pattern, which is similarand superior to that of a gravity heat pipe, breaks the bottleneck carriedout by the low thermal conductivity of PCM and endows the heat storagerwith high thermal performance. On the basis of theoretical analysis ofheating time, power distribution, temperature difference between theinside and outside of the granular PCM, naphthalene as the HTF andelectrically heated rod as the heat source, a series of experiments arecarried out to study the properties of the designed phase change heatstorager. Both the theoretical and experimental results show that thecomposite PCM has excellent heat storage properties and thermostability;in comparison with the traditional heat storage, thermal performance ofthe newly designed phase change heat storager is no longer limited by thelow thermal conductivity of the PCM. The granular form-stable PCM canstore and release heat in a short time, temperature difference between thePCM and the HTF is merely about3℃.