聚碳酸酯板材一维非稳态传热实验和模拟计算

对聚碳酸酯(PC)板材热成形的具体边界条件进行分析和简化,得出传热过程模型,此热传导过程为一个一维非稳态传热过程。利用小型实验烘箱实验得出不同厚度的PC板材,不同加热方式的热透时间。同时,通过运用Abaqus有限元模拟软件对不同厚度PC板,不同加热方式的传热过程进行模拟计算,实验结果与模拟结果进行对比,能够很好的吻合。

PVT光伏光热系统结合地源热泵的应用性研究

基于PVT系统存在太阳能间歇性,无法保证光热转换连续进行的特点,以及存在集热后太阳能电池背板温度过高,导致电池板光伏发电效率下降的缺陷。采用地源热泵与PVT系统相结合,解决了单纯PVT系统在日照不充足情况下热量不能连续稳定供应的问题,提高了系统的热能利用率。同时系统采用定温加热、温差循环技术,有效降低了太阳能电池背板的温度,提高了太阳能电池的光伏发电效率和地源热泵的工作效率以及系统在不同工况下连续运行的可靠性和稳定性。

Principal Component Analysis （PCA） on Multivariate Data of Lard Analysis in Cooking Oil

Discrimination of fatty acids （FAs） of lard in used cooking oil is important in halal determination. The aim of this study was to find the information related to the changes FAs of lard when frying in cooking oil. Quantitative analysis of FAs composition extracted from a series of experiments which involving frying cooking oil spiked with lard at three different parameters; concentration of spiked lard, heating temperatures and period of frying. The samples were analyzed using Gas Chromatography （GC） and Principal Components Analysis （PCA） technique. Multivariate data from chromatograms of FAs were standardized and computed using Unscrambler X10 into covariance matrix and eigenvectors correspond to Principal Components （PCs）. Results have shown that the first and second PCs contribute to the FAs mapping which can be visualized by scores and loading plots to discriminate FAs of lard in used cooking oil