提出了基于蒙特卡洛随机近似的热探针方法,该方法以热探针微分方程的精确解为基础,可同时进行热导率、比热容等热物性的测量。对水、甘油、硅油、酒精的测量结果显示,该方法热导率测量的最大相对误差仅为0.7%,比热容相对误差绝对值的平均值为2.6%,最大相对误差为3.8%。利用该方法对快速裂解所生产的生物油的热导率和比热容进行了测量,给出了温度、有机助剂对生物油热导率和比热容的影响,并对结果进行了分析。
A new thermal probe method for simultaneously measuring thermal conductivity and special heat capacity based on a Monte Carlo inversion was presented. The accuracy of the experimental system was checked against water, glycerol, silicon oil, and ethanol. The results show: (1)the relative deviation of thermal conductivities was about 0.3% on an average, and was below 0.7% for the ethanol, which was much lower than that by other thermal probe methods, (2)the mean deviation of special heat capacity was 2.6% and the maximal deviation was about 3.8%. The thermal conductivities and special heat capacities of bio-oil produced by pyrolysis reactions from rice hull were measured with this system. The effects of temperature and the organic assistants (methanol, ethanol and ethyl acetate) added in the bio-oil on the thermal properties were analyzed.