几种石墨在熔融Solar Salt中的热腐蚀行为

Hot-corrosion behavior of several kinds of graphite in molten solar salt

Solar Salt是太阳能光热发电的最佳传热介质,石墨材料具有良好的导热性和化学稳定性.为研究4种不同成型工艺制备的石墨材料在熔融Solar Salt中的热腐蚀行为,将已加工的石墨试样浸入装有熔盐的坩埚中并置于马弗炉中进行热腐蚀试验,每隔4h取出试样并称重直至试样完全破坏.通过XRD、SEM和OP等方法研究热腐蚀试样的形貌和相组成.研究发现:4种石墨材料耐熔融Solar Salt腐蚀性能强弱的顺序为细结构石墨、等静压石墨、9#石墨和冷压石墨.石墨材料的石墨化度越大,其耐熔融Solar Salt热腐蚀能力就越强.几种石墨在熔融盐中的破坏主要是物理反应所致,碳元素并没有与熔盐发生化学反应形成新的物相.

Solar salt is the best heat transfer medium of solar thermal power system. Graphite material has good thermal conductivity and chemical stability. In order to study hot-corrosion behavior of four graphite materials prepared with different molding process in molten solar salt, the obtained graphite sam- ples are immersed into a crucible with molten solar salt and put in muffle furnace, then taken out and weighted every four hours until the samples are completely damaged. The morphology, microstructure and phase composition of hot-corrosion samples are study with XRD, SEM and OP methods. It is found by the research that the order of hot-corrosion resistance of these four graphite in molten solar salt is as fol- lows： structure graphite, isostatic graphite, 9# graphite, and cold pressed graphite. The greater the de- gree of graphitization was, the stronger the hot-corrosion resistance ability of the graphite in molten salt would be. The damage of graphite in molten salt is mainly caused by physical reaction and the element of carbon does not take part in reaction with molten salt to form a new phase.