Análise experimental de um aquecedor do tipo radiador assistido pelo princípio de funcionamento de termossifões

Abstract

Thermal efficiency plays a crucial role in various industrial and engineering applications, serving as a fundamental indicator to assess the performance of these systems. Radiator-type heaters are known for their compact feature, allowing for large thermal exchanges in a reduced volume. Systems based on the thermosyphon operating principle harness the latent heat of vaporization of a working fluid in a twophase condition to transfer heat. This process involves heat absorption in the evaporator region, which is then transported to the condenser region, where the working fluid condenses and returns to the evaporator, completing the thermodynamic cycle. The thermal efficiency of these passive devices depends on several parameters, including the thermophysical properties of the working fluid, system geometry, and the temperature difference between hot and cold regions. In this study, an experimental analysis of the operation of two heaters was conducted. One of them, a commercial heater, was kept as a reference, using oil as the working fluid; while in the other heater, prototype, some modifications were made to operate based on the thermosyphon principle. In the prototype, distilled water was used as the working fluid and filled with different filling ratios (40, 50, and 60%), to assess temperature distribution, working pressure, and the time required to reach steady-state conditions. The results lead to the conclusion that the prototype, when filled with a filling ratio of 40%, exhibits the best optimization characteristics compared to the others. It is 62% faster in reaching operational temperature, has a thermal gradient of 3ºC compared to the commercial heater's 15ºC, and conversely exhibits a maximum temperature 10ºC lower than the commercial heater. Overall, this device proves to be a promising alternative compared to commercial heater, providing comparable energy consumption to ensure thermal comfort in household environments.