采用基于混合原理的动态半开放方法测量保温砖的高温比热容

摘要

保温砖是铸造中的常用材料,比热容是材料重要的热物性参数,也是铸件凝固过程数值模拟所需参数.保温砖为多孔材料,其高温比热容测量困难.针对这种情况,提出了基于混合原理的动态半开放比热容测量方法,并研制了相应的比热容测量仪.采用已知比热容的蓝宝石试样进行标定,试验值和理论值误差在6.3％以内.采用此方法测得了进口和国产两种保温砖在30～760℃的比热容曲线.%Insulating brick is widely used in casting production. Its specific heat capacity is one of the important thermal properties and crucial for numerical simulation of solidification process. Because of its porous characteristic, it is hard to measure the specific heat capacity at high temperatures. In this paper, a half-open dynamic measurement method based on hybrid principle was presented and a measurement device was established. Sapphire with given standard value of specific heat capacity is used to calibrate the system; the error is less than 6.3%. Specific heat capacity of two different kinds of insulating bricks were measured in the temperature range from 30 °C to760°Co