ASSESSMENT OF DIFFERENT HYPERVAPOTRON FIN PROFILES FOR THE MULTIPHASE COOLING OF POWER VACUUM TUBES

In high-power electronic applications, hypervapotrons are commonly used for efficient heat dissipation. The present study relates to the hypervapotron application in vacuum tubes of the ion cyclotron radio frequency source used in fusion reactors. The vacuum tube's outer jacket utilizes hypervapotron (HV) fins for cooling purpose. The initial phase of indigenous vacuum tube development involves the design and development of this jacket. This research examines different types of hypervapotron fin profiles and investigates the wall temperatures of the cooling jacket using a multiphase cooling approach. The objective of the study is to safeguard the expensive vacuum tube against potential failure caused by inadequate cooling. The analysis includes five types of fin profiles: rectangular, concave, trapezoidal, U-shaped, and inverted trapezoidal. The study employs Ansys CFX software to illustrate the variation in temperature across the fins. The results indicate that the wall temperatures vary across all the distinct types of fin profiles, with the flow and heat flux values. Comparing the results with the wall temperature of the U-type profile indivcates importance of fins' shape in heat transfer. In addition, a simulation has been conducted to model the fundamental impact of wall surface roughness. The increase in surface roughness value enabled the cooling jacket to maintain the lower wall temperature at the given heat flux values.