Design and verification of ultra-high temperature lithium heat pipe based experimental facility

Abstract

Lithium heat pipe has broad applications in heat pipe cooled reactors and hypersonic vehicles due to its ultra-high working temperature which is around 1700 K. In this paper, a lithium heat pipe based experimental facility has been designed to test the heat transfer performance of the lithium heat pipe. A simplified mathematical model of heat pipe has been implemented into a CFD approach, which is used to verify the design of lithium heat pipe and its experimental facility. Results showed that the CFD approach is in good agreements with some well-known existing models and experimental data, and deviation between the results is within 5% range. The adjustment range of mixed gas thermal resistance and cooling water flow rate was obtained by analyzing the effects of different cooling conditions on the performance of the experimental facility. It is necessary to ensure the cooling water flow rate is above 0.11l/h to prevent water boiling when the heating power is10kW around, and the optimal proportion of helium is 70% -90%.The operation characteristics of the lithium heat pipe under unsteady state with varying heating power were simulated numerically. The results show that the proportion of helium must be less than 60% for normal operation of the lithium heat pipe. This work provides a reference and numerical verification for the design of lithium heat pipe based experimental facility, which can be used to reveal the heat transfer mechanisms of the lithium heat pipe during the experiment.

Numerical Simulation of Heat Pipe Thermal Performance for Aerospace Cooling System Applications

“…More recently, several research projects have been adopting a more practical approach, coupling numerical investigations with extensive experimental campaigns. Tokuda and Inoue [36] investigated the thermal performance of an oscillating heat pipe with sodium as a working fluid, while Hu et al [22] designed a lithium heat pipe-based experimental facility to test the heat transfer performance of a lithium heat pipe. The work of Hu et al is very interesting because the description of the experimental setup is complemented with a simplified mathematical model implemented into a CFD approach, which is used to verify the design of the lithium heat pipe and its experimental facility.…”

“…More recently, efforts to create new extraterrestrial outposts or reach farther space destinations are pushing researchers to develop space nuclear reactors. These systems will require extreme cooling capabilities, which might be granted by ultra-high-temperature heat pipes [22].…”

Review of reactor conceptual design and thermal hydraulic characteristics for heat pipe in nuclear systems

“…A startup scheme based on the analysis of transient thermohydraulic behavior during cold start-up was proposed for a three-stage HPCR with high safety. Hu et al (2022) developed a network code in Python specifically for ultrahigh temperature lithium HPs. The study found that increasing the wall thickness and wick thickness of a HP leaded to an increase in the transition time.…”