A heat pipe calculation method based on the two-phase mixture model of porous medium

Abstract

This paper proposes a new method for calculating heat pipes, in which the porous wick inside the heat pipe is described by the two-phase mixture model (TPMM) of porous medium based on the modified temperature model that adopts the local thermal equilibrium assumption. The capillary pressure inside the wick is characterized by the Leverett capillary pressure model. This model can calculate the two-phase flow within the heat pipe wick at the macroscopic scale level and achieves a full-field coupled solution for the wick-vapor-wall flow and heat transfer process by a specific coupling method. Finally, the paper conducts a coupled heat transfer calculation for a heat pipe using potassium as the working fluid, verifies the correctness of the model and solution method by comparing it with the experimental results, and studies the flow and phase transition patterns of the heat pipe under multiple heating and different overload conditions. Compared with the traditional single-phase porous medium model of heat pipes, the new model can consider phase transition within the porous wick. While compared with pore-scale methods, the macroscopic research scale of the new model can reduce the computational resources required.