Thermal analysis of annular space of vacuum insulation in steel jacketed directly buried heating pipeline
Heating pipeline employs vacuum insulation to improve the insulating effect and reduce the corrosion, and hence, increase the heat transfer efficiency and reliability of heating network, further, the building energy efficiency. Experiments were performed to measure the heat transfer of vacuum layer of steel jacketed vacuum insulated heating pipelines, at inner steel cylinder of 200～300 ℃, at the vacuum of 10～1013mbar,respectively. Methods to calculate the heat transfers and equivalent thermal conductivities of vacuum layer were developed based on experimental data and theory of aerothermodynamic for rarefied air. Results shows agreement with the experimental data for the error is below 8.6％. The heat transfer by convection in vacuum insulation of steel jacketed heating pipeline is not neglectable. The pressure in vacuum insulation should be controlled below 20mbar to achieve desirable insulating effect. All these may be helpful to develop a perfect vacuum insulated heating pipeline product.
vacuum insulation directly buried pipeline equivalent thermal conductivity heat transfer
YANG Fan NA Wei ZOU Ping-hua
China University of Mining and Technology Department of Building Thermal Engineering, Harbin Institute of Technology, Box223, Harbin 150090, C
国际会议
哈尔滨
英文
400-402
2007-01-15（万方平台首次上网日期，不代表论文的发表时间）