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摘 要 ：本文通过理论分析得出工质R134a在0℃～100℃低加热温区范围内相对于工质水、R123、乙醇可能具有更佳的蒸发和冷凝特性。实验研究了两种不同管内径纯铜管，其中一组管内径大于闭式环路型自激振荡热管的临界管径，另一组小于临界管径。本文这部分主要展示了管内径大于临界管径的装置在不同常壁温下的传热性能。研究结果表明：常壁温边界下发生脉动的参数是输热量，当量有效热导率和热端输热量在稳态时具有同相变化趋势，R134a的确具有良好的蒸发、冷凝特性，即使管内径超出自激振荡热管的临界管径，在该温区范围内，最小有效热导率仍为铜导热系数的百多倍，是一种高效的传热介质，有望在微通道闭式环路脉动热管中使用。 关键词： 自激振荡热管；传热性能，当量有效热导率，R134a Experiment investigation on heat transfer of Close loop self-oscillating heat pipe Liu L.H1,2 Chen G.M2 Zhang G.Y1 Jiang S.Z1 Zou J.J1. 1. Zhejiang Sci-Tech University. Hangzhou 310033, China; 2. Zhejiang University, Hangzhou, 310027 Abstract: This paper infers working fluid R134a having more better properties of evaporating and condensing than water, R123 and ethanol at 0℃～100℃ low temperature range by theory analyzing. Two different internal diameters pure copper tube has been experimented, which diameter is bigger than critical one of close loop self-oscillating heat tube and the other is smaller than it. This part of the paper reports the thermal performance of bigger one at a different constant wall temperature. The research shows that pulsating parameter is heat input at constant wall temperature. Nondimensional effective conductivity and heat input have same variety trend when steady-state. And R134a is truely a nice working fluid of better evaporating and condensing characteristic, even though the device internal diameter go beyond critical one, the minimum effective thermal conductivity is one hundred more times than coppers. It proves R134a is a high effective heat transfer working fluid and is hopeful to be used in microchannel close loop self-oscillating heat pipes. Keywords：self-oscillating heat pipe ; heat transfer; nondimension effective conductivity; R134a Vol.14,No.4,P436－440