Experimental Investigation on Axially Grooved Multi-branch Heat Pipe

Abstract

In modern world, heat pipes have shown their considerable importance in cooling of electronic circuits, super computer systems, aerospace thermal management, nuclear reactors and so on. Conventional heat pipes are used to cool single heat source in an electronic circuit. Nowadays, heat pipes are developed which can provide cooling to multiple heat sources due to space constrain in aerospace and electronic systems. Multi-branch heat pipe is a ‘T’ shaped heat pipe with three branches in which there are two evaporator sections and one condenser section. Axially grooved multi-branch heat pipe (AGMBHP) is experimentally investigated for various parameters in the present work. Experimental investigation is carried out for optimum filling ratio 150%, and results are presented in terms of thermal resistance, dynamic characteristics, temperature distribution, heat transfer co-efficient and cooling water flow rate. In horizontal orientation, AGMBHP is capable to transfer 240 W heat load with minimum total thermal resistance of 0.192 °C/W at 150% filling ratio. Performance of heat pipe is further investigated for gravity assisted orientation (GAO), anti-gravity orientation (AGO) and compound orientation (CO) for heat load range of 0-200 W or up to dry-out condition. The heat transfer co-efficient are found and compared for different orientations which suggests horizontal orientation (HO) to be optimum. AGMBHP is compared with MBTHP in terms of thermal resistance and effective thermal conductivity. A C programming code is generated to calculate overallheat transfer co-efficient and LMTD for water cooled condenser of AGMBHP.