Determination Of Thermal Conductivity And Research Of Heat Transfer Performance Of The Edible Vegetables Oil

Fat is an indispensable important material on diet and modern food industry. It was widely used in industry, medicine, machinery, and other fields. According to the existing literature, it just showed the thermal conductivity data measured below 120 ℃, the span of temperature is too big, it was lack of the thermal conductivity data measured over 120, the ℃equipment design about heat transfer and heat equipment was restricted seriously in oil processing process. Therefore, it is very important for the equipment selection and actual production in fat and oil production to use more accurate and reliable technique to study the thermal date.Hot Disk thermal constants analyzer is a new kind of more accurate and convenient measurement technology that based on the transient plane source. It was widely used to measure the thermal conductivity of solid, but rarely applied to measure that of liquid. So we need study suitable heating power and test time for liquid through experiment to lay the foundation for the accurate determination of edible oil’s thermal conductivity. Using the instrument to measure the thermal conductivity of sunflower oil, wheat germ oil, corn germ oil, grape seed oil and soybean oil with different heating power, measuring time and temperature, selected the optimal experimental parameters programs, discussed the impact on thermal conductivity by heating power, measuring time and temperature.The Study of the effect on thermal conductivity of edible oil by heating power, measuring time and temperature was based on TPS 2500 S device produced by Hot Disk AB, 5465 probe sensor, insulating film made of Teflon, radius of 3.189 mm and high-temperature sample holder. The experiment measured that the best heating power of 30 mW for the oil above, the best measuring time of 3s for wheat germ oil and soybean oil, the best measuring time of 5s for sunflower oil, corn germ oil and grape seed oil. After comparative and analysis showed changes rule of five oil with measuring time, heating power, temperature is almost the same.Determine coefficients all above 0.95, indicated that the curve of polynomial fitting close to the data point very well; Standard deviation all less than 0.0033, represented the dispersion of data to average value is small; Confidence level less than 0.0001,above the level of 0.9999, the results showed the true on statistical significance.F value larger than 134.6, and P value is 0 of several vegetable oil, usually when significance level less than 0.05 considered that the result is real. P value is 0 and less than 0.05 can obtained there was significantly correlation between thermal conductivity of several vegetable oil and temperature. By F test and P test description for this regression model can predict the relationship between thermal conductivity of several vegetable oil and temperature. The thermal conductivity of the oil above ranged from 0.1720W/mK to 0.2340W/mK. The study can fill gaps in thermal conductivity of oil, it lay the foundation of oil processing technology and equipment selection.