五元氯化物熔盐的制备及其传蓄热性能

RESEARCH ON PREPARATION AND PROPERTIES OF QUINARY CHLORIDE MOLTEN SALT

在四元低共熔盐NaCl-KCl-MgCl2-CaCl2基础上制备出含Li五元氯化物熔盐材料,采用差示扫描量热法（DSC）确定含Li五元氯化物熔盐低共熔点和组成,测定其热物性、热稳定性,研究该熔盐对铁基AISI 316L、310S、321不锈钢和镍基Inconel 625合金的腐蚀性。结果显示,该熔盐熔点为356.5℃,相变潜热为150.9 J/g;熔盐液体在650℃的比热为1.208J/（g·K）、密度为1.699g/cm^3、黏度为2.56cp、热扩散系数为0.0104mm^2/s、导热系数为0.0213 W/（m·K）;封闭容器中,五元熔盐高温稳定性较好;在低氧分压下,对上述几种合金的腐蚀性按310S、321、316L、Inconel 625顺序依次减小。

The DSC method was used to determine the low eutectic melting point and composition of the lithiumcontaining quinary NaCl-KCl-MgCl2-CaCl2 eutectic salt mixture,which was based on the quaternary chloride eutecticmixture.Preparation of the molten salt materials based on the eutectic composition of quinary salt mixture.Thermophysical properties,thermal stability and dynamic circulation heat storage and discharge characteristics were measuredto characterize the heat transfer performance of the quinary chloride eutectic mixture.Then the corrosion of the moltensalt to iron-based AISI 316 L,310 S,321 stainless steel and nickel base Inconel 625 alloy was determined.Results showthat the melting point of the molten salts is 356.5 ℃,heat of fusion is 150.9 J/g,the average heat capacity of liquid saltat 650 ℃ is 1.208 J/（g？K）,the density is 1.699g/cm^3,viscosity is 2.56cp,thermal diffusivity is 0.0104 mm^2/s,thethermal conductivity is 0.0213 W/（m？K）.The quinary salt mixture showed excellent thermal circling stability under theisothermal condition.Meanwhile,in low oxygen partial pressure,the corrosion of the quinary salt mixture to the fouralloys is follow the sequence of 310S,321,316L,Inconel 625 decrease in turn.