新型相变材料回填的地埋管传热特性研究  

Research on Heat Transfer of a Borehole Ground Heat Exchanger with Novel Phase Change Backfill Materials

作　　者：何伟[1] 赵万方 郑晓宇[1] HE Wei;ZHAO Wan-fang;ZHENG Xiao-yu(College of Civil Engineering,Hefei University of Technology)

机构地区：[1]合肥工业大学土木与水利工程学院,安徽省合肥市230009

出　　处：《建筑热能通风空调》2021年第8期18-24,共7页Building Energy & Environment

摘　　要：本研究制备了新型癸酸-月桂酸/膨胀石墨复合相变材料并通过数值模拟研究了不同复合相变材料回填含量及不同运行模式下的地埋管换热器传热特性。复合相变材料中膨胀石墨与脂肪酸的最佳比例确定为10:100。本文提出了相变材料回填的地埋管传热模型并进行验证,研究了不同回填材料及运行模式下地埋管换热量,钻孔内液相比等参数的动态变化规律。数值模拟结果表明,U型地埋管系统的换热量随回填中相变材料含量的提高而提高,但温度恢复性能逐渐减弱。在相同的相变材料回填含量下,换热量随系统启停时间比的升高而升高,但平均能效比及恢复性能随启停比升高而降低。此外,高相变回填含量的换热系统不适宜在高启停比下长期运行。Heat transfer in a ground heat exchanger(GHE) system with a novel capric acid-lauric acid eutectics/expanded graphite PCM composite was investigated. PCM composite was prepared and analyzed. The optimal mass ratio between fatty acid and expanded graphite was 10:100. Thermal performance of GHE system with different mass ratio of PCM mixed in the backfill material was simulated and higher PCM ratio yielded a higher heat exchange performance but worse recovery performance. GHE operated with different discontinuous running mode was studied.The results show that a lower on/off time ratio should be preferred in the case with high latent heat in backfilling for better recovery.

关 键 词：相变材料 地埋管换热器 间歇运行 数值模拟 

分 类 号：TU83[建筑科学—供热、供燃气、通风及空调工程]