Development and Performance Analysis of a Novel Multi-Stage Microchannel Separated Gravity Heat Pipe for Compressor Room Cooling

Traditional multi-stage separated heat pipes (SHPs) face limitations in independently setting operation parameters for each stage. To address this issue, this paper presents a novel independent multi-stage microchannel Separated Gravity Heat Pipe (SGHP) for air compressor room cooling. The innovative structure and working principle of this novel multi-stage SGHP were introduced. Furthermore, numerical investigations on a single stage of the SGHP were then conducted to study the gas–liquid two-phase flow characteristics and phase-change heat transfer performance. Experimental research on a three-stage SGHP was carried out to further explore the impact of the filling ratio combinations and the temperature difference between the hot and cold ends on the heat transfer performance of the SGHP. The results show that the temperature difference between the hot and cold ends affects the flow pattern of the working fluid, which has a vital effect on the heat transfer performance of the SGHP. The optimum filling ratio combination of the three-stage SGHP depends on the temperature difference between the hot and cold ends. The optimum filling ratio combination is 37%/37%/30% at low temperature difference conditions and 43%/37%/37% at high temperature difference conditions, respectively. The highest heat transfer capacity of the three-stage SGHP reaches 15.3 kW, and the peak heat recovery efficiency is 74.0%. The findings provide a crucial foundation for developing novel independent multi-stage SGHP in compressor room cooling and similar industrial settings, promising high potential to reduce energy consumption and operational costs.