竖直U型地埋管换热器热短路抑制措施的分析

Analysis of the Measures to Prevent the Thermal Short-cut of a Vertical U-shaped Embedded Tube Heat Exchanger

建立了单U型地埋管换热器三维瞬态数值分析模型,对抑制地埋管换热器"热短路"的各种措施进行了数值模拟。在不同载流体流速和回填料导热系数条件下,分别对隔热板式、保温套式地埋管换热器和未采取任何"热短路"抑制措施的普通地埋管换热器整体传热性能进行了研究,获得了不同"热短路"抑制措施对埋管换热器整体传热性能的影响规律;通过对影响埋管换热器整体传热性能"热短路"抑制措施的对比分析,并结合地埋管换热器实际工程运行环境,提出在工程实践中不必针对埋管换热器的"热短路"现象采取任何额外的抑制措施的建议。

Established was a three-dimensional transient numerical model for analyzing a single U-shaped embedded tube heat exchanger and numerically simulated were various measures to prevent the 'thermal short-cut' of the embedded tube heat exchanger.Under various flow carrier speeds and heat conductivity coefficients of the backfill material,the overall heat transfer performance of a heat isolation plate type and a heat isolation sleeve type embedded tube heat exchanger as well as a common embedded tube heat exchanger for which no measures was taken to prevent any thermal short-cut were studied respectively.The law governing the influence of different 'thermal short-cut' prevention measures on the overall heat transfer performance of the embedded tube heat exchangers was obtained.Through a contrast analysis and comparison of the 'thermal short-cut' prevention measures,which influence the overall heat transfer performance of the embedded tube heat exchangers,and in combination with the operating environment of actual embedded tube heat exchanger projects,the authors proposed that in practical engineering projects,it is not necessary to take any additional measures to prevent any thermal short-cuts of embedded tube heat exchangers.