Abstract Boiling hysteresis is a side effect that usually occurs with overshot temperature before steady boiling, often noted as a start-up problem. This phenomenon tends to emerge when porous surfaces are used to enhance boiling heat transfer performance. It is important to reduce or eliminate hysteresis before various micro−/nanoporous surfaces can be deemed acceptable in the thermal management industry. In this study, a two-layer composite surface (TLCS) with a copper forest structure at the bottom and micro-nano biporous structure at the top showed good enhancement at a heat transfer coefficient of 340% and critical heat flux of 67% compared to a plain copper surface with water as the working fluid at atmosphere. However, boiling hysteresis occurred on TLCS; the highest wall superheat temperature difference between steady boiling and the start-up process was approximately 13.5 K at 140 W cm−2. When TLCS was modified with Polytetrafluoroethylene (PTFE), the temperature difference at the same heat flux was less than 0.5 K, demonstrating that the boiling hysteresis phenomenon was successfully eliminated.

中文翻译：

---

PTFE 改性多孔表面：消除沸腾滞后

摘要 沸腾滞后是一种副作用，通常在稳定沸腾之前出现过冲温度，通常被称为启动问题。当使用多孔表面来增强沸腾传热性能时，往往会出现这种现象。在各种微/纳米多孔表面在热管理行业中被认为是可接受的之前，减少或消除滞后是很重要的。在这项研究中，底部为铜森林结构，顶部为微纳米双孔结构的两层复合表面 (TLCS) 在传热系数为 340% 和临界热通量为 67% 时表现出良好的增强效果。在大气中以水为工作流体的纯铜表面。然而，在 TLCS 上出现沸腾滞后；稳定沸腾和启动过程之间的最高壁过热温差在 140 W cm-2 时约为 13.5 K。当TLCS用聚四氟乙烯（PTFE）改性时，相同热通量下的温差小于0.5 K，证明沸腾滞后现象被成功消除。