Experimental Analysis of Heat Storage and Release of Binary Methanol Aqueous Solution Pulsating Heat Pipe Phase Change Accumulator

Xiaohui Lu,Shibo Cao,Xiaoxue Luo,Changzhen Zou

doi:10.3389/fenrg.2022.798522

Abstract

To improve the problems of energy shortage and low utilization rate, this paper designed a set of pulsating heat pipe (PHP) devices coupled with phase change energy storage material. Further, the binary methanol-water solution is proposed as a novel experimental filling medium to enhance the heat transfer performance of the device. The fluid flow model of the PHP was analyzed via experiment and simulation. Besides, the heat storage and release performances of the PHP at different flow rates, different heating temperatures, different filling mediums, and different filling ratios are investigated. The results show that when the filling medium (binary methanol-water solution) possesses the filling ratio of 0.6 (methanol and water are each 0.3), the heat source inlet flow is 0.60 m3/h, the heat source heating temperature is 120°C, and the PHP is at the best heat storage performance. During the exothermic process, the lower the initial temperature of cooling water, the higher the heat recovery rate. Thus, it can be concluded that the selection of an appropriate filling medium and the optimal parameters to enhance heat transfer can have a broader application prospect in the field of waste heat recovery.

Highlights

At present, the main problems of energy in China are low energy resources per capita, a large gap between supply and demand, high energy consumption intensity, low efficiency, complex structure, and serious environmental pollution (Wei, 2016; Dong et al, 2017; Wei et al, 2020)
The VOF model is used for solving in Fluent software, and the boundary condition of the evaporation section of the pulsating heat pipe (PHP) is set to the constant temperature of 120°C and the wall thickness of 1 mm, the temperature boundary condition of the heat storage section is set to 20°C, and the wall thickness is 1 mm
At the beginning of the heat storage section, as the heating temperature increases, the inner wall of the heat pipe will attach to the liquid to generate a vaporization core

Summary

Introduction

The main problems of energy in China are low energy resources per capita, a large gap between supply and demand, high energy consumption intensity, low efficiency, complex structure, and serious environmental pollution (Wei, 2016; Dong et al, 2017; Wei et al, 2020). In the field of energy storage, such as the recovery and utilization of ship waste heat, there is a great demand for efficient heat transfer devices, which is a hot research topic at present. After the oil crisis in the late 1970s, the use of phase-change material (PCM, Phase-change material) for latent heat storage has become an efficient and practical heat storage technology with the large latent heat capacity and near constant temperature, which has a very broad application prospect (Shiina, 2006; Hoseinzadeh et al, 2018; Konuklu, 2018; Murthy et al, 2021).

Methods

Results

Conclusion