An experimental study on thermal properties of vacuum insulation for steel jacketed heating pipeline
Heating pipeline employs vacuum insulation to improve insulating effect and reduce corrosion, and hence, increase heat transfer efficiency and reliability of heating network, further, building energy efficiency.Experiments was performed to measure heat transfer and equivalent thermal conductivity of vacuum insulation with pressures from 0.5 to 1013 mbar for temperatures of inner steel pipeline at 200 ～ 300 ℃. Heat transfer of this pipeline is a strongly degressive function of vacuum pressure of insulation, especially when it is below 50mbar. Equivalent thermal conductivity of insulating material layer is lower and drops sharper with vacuum pressure than that of vacuum layer, distinctively. As vacuum pressure decreases from 1013mbar to 10mbar (Inner steel pipeline is at 250℃ e.g. ), reduction of equivalent thermal conductivities of vacuum layer is about 3 times greater than that of insulating material layer. Vacuum pressure of this pipeline should be controlled below 20mbar to achieve desirable insulating effect.
thermal properties vacuum insulation heating pipeline equivalent thermal conductivity steel jacket
NA Wei ZOU Ping-hua
Department of Building Thermal Engineering, Harbin Institute of Technology, Box223, Harbin 150090, China
国际会议
哈尔滨
英文
375-377
2007-01-15（万方平台首次上网日期，不代表论文的发表时间）