对 3 种复合吸液芯微细直径热管( 外径 2 mm) 进行了理论分析和实验研究， 3 种 吸液芯分别为铜粉丝网复合吸液芯( SMCP) 、泡沫铜丝网复合吸液芯( SMCF) 和复合丝网 吸液芯( MSM) ; 结合毛细极限理论分析了这 3 种热管的极限传热功率，并分析其在不同 充液率下的极限传热功率、轴向温度分布和蒸发冷凝热阻特性． 结果表明: SMCP、 SMCF 和 MSM 热管的最佳充液率分别为 110%、 95%和 90%，此时其极限传热功率均为 7 W，与 理论计算值接近; 3 种热管的轴向温差随着加热功率的增大而增大，其轴向温差最大值分 别为 4. 22、 4. 20 和 4. 90℃; 随着加热功率的增大，蒸发热阻逐渐增大; 充液率较低时，冷 凝热阻变化幅度不大，充液率较高时， SMCP 热管的冷凝热阻出现较大幅度波动，而 SMCF 和 MSM 热管的冷凝热阻相对稳定; 当3 种热管的充液率为各自最佳充液率且加热功率为 7W时，其蒸发热阻分别为 0. 437、 0. 493 和 0. 591 ℃ /W，冷凝热阻分别为 0. 167、 0. 106 和 0. 110℃ /W． 

In this paper theoretical and experimental studies are conducted on three kinds of micro-diameter heat pipes (MDHPs， their outer diameter is 2 mm) with composite wick． The composite wicks consist of copper powdermesh (SMCP)，copper foam-mesh (SMCF) and mesh-mesh (MSM)． By referring to the capillary limit theory， the heat transfer power of the three kinds of MDHPs is analyzed and at the same time，maximum heat transfer capability under different filling ratios， the axial temperature distribution and the evaporation and condensation thermal resistances are analyzed． The results indicate that the maximum heat transfer capabilities of the three are 7W，with the corresponding optimum filling ratios of SMCP，SMCF and MSM being 110%，95% and 90% respectively， which are close to the theoretical values of capillary limit． The axial temperature differences of MDHPs increase with the heating power，and the maximum values are 4. 22，4. 20 and 4. 90 ℃ respectively． With the increase of heating power， the evaporation thermal resistance increases gradually． The change of condensation thermal resistance is small under low filling ratio． With high filling ratio，condensation thermal resistance of SMCP heat pipe fluctuates greatly，while condensation thermal resistances of SMCF and MSM heat pipes are relatively stable． When the filling ratios of the three kinds of MDHPs and their respective optimum filling ratios and heat transfer performance reach 7W， their evaporation resistances of MDHPs are 0. 437，0. 493 and 0. 591℃ /W，and their condensing heat resistances are 0. 167，0. 106 and 0. 110℃ /W，respectively．