Development of a Heat Pipe heat Exchanger Performance Test Rig for Waste Heat Utilization and Thermal Performance Test

This paper aims to establish core technologies for heat pipe heat exchanger systems that effectively recover waste heat from high-temperature industries. To this end, it was developed a heat exchanger thermal performance test rig capable of accurately simulating high-temperature hot gas environments above 200°C. During the initial commissioning of the test rig, severe temperature deviations at the inlet were identified and improved to within 1°C through the installation of flow control baffles and straighteners, thereby ensuring the reproducibility and reliability of the test results. Using the developed test rig, the thermal performance of three prototype heat pipe heat exchangers with and without fins was evaluated. The test results showed that the copper-copper fin type heat exchanger achieved a maximum performance improvement of 47.3% (maximum effectiveness of 81%) compared to the bare copper type heat exchanger, clearly demonstrating the difference in thermal performance due to the attachment of fins. Next, the difference in thermal performance due to changes in NTU was experimentally verified in heat exchangers of the same copper-copper fin type heat exchanger. Additionally, through thermal shock reliability testing, it was confirmed that the effectiveness of the heat exchanger prototype remained stably within 1.1%, verifying that long-term reliability can be ensured even under harsh operating conditions. This study provides an important technical foundation for the commercialization of high-temperature waste heat recovery technology and is expected to contribute to increased energy efficiency and reduced carbon emissions.