表面强化管外池沸腾传热特性研究

为实现节能降耗,开发了多种强化沸腾传热的高效换热管。以水为工质,在0.1MPa下对垂直光管、烧结多孔管和T槽管进行了池沸腾传热实验研究,并分析了沿管子轴向的温度分布。实验结果表明,烧结多孔管与T槽管能显著降低起始沸腾过热度、强化沸腾传热:烧结多孔管和T槽管的起始沸腾过热度比光管的低1.5K左右;烧结多孔管和T槽管的核态沸腾传热系数分别为光管的2.4～3.2倍和1.6～2.0倍。此外,烧结多孔管和T槽管能降低相同热流密度下的壁面温度,且有利于降低管子轴向的温差。

Characteristics of pool boiling heat transfer from enhanced porous surface tubes

For the sake of energy conservation and emission reduction,numerous types of highly efficient heat transfer tubes have been developed to enhance nucleate boiling heat transfer.An experimental investigation on pool boiling heat transfer of saturated water from vertical plain copper tube and two enhanced surface tubes: sintered coated porous tube(High Flux) and mechanically fabricated porous surface tube(Gewa-T) at 0.1 MPa pressure was presented.The overall heat transfer coefficient,temperature distribution and temperature difference along the axial direction of these tubes were analyzed.The results show that the enhanced surface tubes can lower the incipient boiling superheat and enhance nucleate boiling heat transfer coefficient compared with plain tube.The incipient boiling superheats of water from enhanced surfaces is 1.5 K lower than that from plain surface.And the nucleate heat transfer coefficient of High Flux tube and Gewa-T tube are 2.4-3.2 and 1.6-2.0 times than that of plain tube.In addition,the enhanced surface tubes can lower the temperature difference along the axial direction compared with the plain tube.