Li Yang, Hou Dexin, Li Feng, Huang Lianghui, Huang Zhihua, Zhang Yuehuan, Zheng Yongping, Song Leipeng, Huang Bingqiang, Fei Zhengshun, Xiang Xinjian
School of Automation and Electrical Engineering, Zhejiang University of Science and Technology, Hangzhou 310023, China.
College of Metrology Measurement and Instrument, China Jiliang University, Hangzhou 310018, China.
Sensors (Basel). 2024 Jun 28;24(13):4206. doi: 10.3390/s24134206.
The thermal properties of bipolar plates, being key elements of polymer electrolyte membrane fuel cells, significantly affect their heat conduction and management. This study employed an innovative approach known as a heat flow loop integral method to experimentally assess the in-plane thermal conductivity of graphite bipolar plates, addressing the constraints of traditional methods that have strict demands for thermal stimulation, boundary or initial conditions, and sample size. This method employs infrared thermal imaging to gather information from the surface temperature field of the sample, which is induced by laser stimulation. An enclosed test loop on the infrared image of the sample's surface, situated between the heat source and the sample's boundary, is utilized to calculate the in-plane heat flow density by integrating the temperature at the sampling locations on the loop and the in-plane thermal conductivity can be determined based on Fourier's law of heat conduction. The numerical simulation analysis of the graphite models and the experimental tests with aluminum have confirmed the precision and practicality of this method. The results of 1060 aluminum and 6061 aluminum samples, each 1 and 2 mm in thickness, show a deviation between the reference and actual measurements of the in-plane thermal conductivity within 4.3% and repeatability within 2.7%. Using the loop integral method, the in-plane thermal conductivities of three graphite bipolar plates with thicknesses of 0.5 mm, 1 mm, and 1.5 mm were tested, resulting in 311.98 W(m·K), 314.41 W(m·K), and 323.48 W(m·K), with repeatabilities of 0.9%, 3.0%, and 2.0%, respectively. A comparison with the reference value from the simulation model for graphite bipolar plates with the same thickness showed a deviation of 4.7%. The test results for three different thicknesses of graphite bipolar plates show a repeatability of 2.6%, indicating the high consistency and reliability of this measurement method. Consequently, as a supplement to existing technology, this method can achieve a rapid and nondestructive measurement of materials such as graphite bipolar plates' in-plane thermal conductivity.
双极板作为聚合物电解质膜燃料电池的关键部件，其热性能对热传导和热管理有显著影响。本研究采用一种创新方法——热流回路积分法，通过实验评估石墨双极板的面内热导率，解决了传统方法对热刺激、边界或初始条件以及样品尺寸有严格要求的局限性。该方法利用红外热成像从激光刺激引起的样品表面温度场收集信息。在样品表面红外图像上位于热源与样品边界之间的封闭测试回路，通过对回路上采样位置的温度进行积分来计算面内热流密度，并基于傅里叶热传导定律确定面内热导率。石墨模型的数值模拟分析以及铝的实验测试证实了该方法的精度和实用性。厚度分别为1毫米和2毫米的1060铝和6061铝样品的结果表明，面内热导率的参考测量值与实际测量值之间的偏差在4.3%以内，重复性在2.7%以内。使用回路积分法对厚度为0.5毫米、1毫米和1.5毫米的三种石墨双极板的面内热导率进行测试，结果分别为311.98W/(m·K)、314.41W/(m·K)和323.48W/(m·K)，重复性分别为0.9%、3.0%和2.0%。与相同厚度石墨双极板模拟模型的参考值相比，偏差为4.7%。三种不同厚度石墨双极板的测试结果重复性为2.6%，表明该测量方法具有高度的一致性和可靠性。因此，作为现有技术的补充，该方法可实现对石墨双极板等材料面内热导率的快速无损测量。
