Experimental study on heat transfer characteristics of medium-temperature oscillating heat pipe with kerosene

As a two-phase heat transfer element, the oscillating heat pipe (OHP) holds significant promise for applications in heat management and thermal energy utilization within the medium-temperature range. To investigate the heat transfer properties of medium-temperature OHPs, a stainless steel OHP that uses an azeotropic mixture of kerosene as the working fluid was developed. The impact of tilt angle and operating temperature on the heat transfer performances of the kerosene OHP under different heating power conditions were studied. Results revealed that: (1) The kerosene OHP exhibits the highest heat transfer performance when oriented vertically. As the tilt angle decreases, the heat transfer capacity decreases significantly, and the kerosene OHP cannot be started when placed horizontally. (2) As the operating temperature increases, the working fluid within the OHP transitions from oscillating flow to a stable one-way flow, resulting in a significant enhancement of the heat transfer capacity of the kerosene OHP. (3) When the OHP is oriented vertically with an operating temperature of 80 °C, the minimum thermal resistance is 0.30 °C/W and the maximum equivalent thermal conductivity is 4046.7 W/(m·K).