Flat-Plate PHP with Gravity-Independent Performance and High Maximum Thermal Load

Abstract

In many energy-related applications, components with high heat loads, such as power electronics, play an important role. Pulsating heat pipes (PHPs) are an effective solution to deal with the increasing heat load of these components. In many real-life applications, the PHP must work against gravity and still be able to operate efficiently. However, the majority of present flat-plate PHP designs do not perform well under this condition. Therefore, this paper presents a flat-plate PHP with a conventional channel design optimized for gravity-independent operation. The PHP was capable of transmitting a heat output of 754 watts in all orientations, while the testing heater in use never exceeded a temperature of 100 °C. No indications of dryout were observed, implying that the maximum thermal load the PHP can handle is even higher. Additionally, three different condenser zone sizes were tested with the PHP. Previously published results indicated that there is a specific range of suitable condenser zone sizes, and performance problems will occur if the condenser zone size falls outside of this range. The findings from this work point in the same direction.

Numerical Study of Heat Transfer and Fluid Flow Characteristics of a Hydrogen Pulsating Heat Pipe with Medium Filling Ratio

“…Figure 1 shows the structure of the closed-loop PHP, which is made by bending a capillary tube back and forth. The PHP not only possesses the advantages of high thermal conductivity, light weight, and no power consumption like traditional heat pipes, but it also offers unique features such as a simple structure, flexible layout, and capability to operate under microgravity [9]. Like other types of heat pipes, the PHP comprises three sections: the evaporator section, the adiabatic section, and the condenser section, and it is partially filled with a certain amount of a working fluid.…”