Effect of bending position on heat transfer performance of R-134a two-phase close loop thermosyphon with an adiabatic section using flexible hoses

The experiments for a Two-phase Closed Loop Thermosyphon (TCLT) of which an adiabatic section was flexible hose, were conducted to describe the effect of bending positions at both joints of vapour and liquid line of TCLT. The evaporator and condenser of TCLT were fabricated from copper tubing, while the vapour and liquid lines were fabricated from Teflon hose. R-134a refrigerant was used as a working fluid. The TCLT was examined with a constant heat flux ranging from 14.2 to 32.6 kW/m2. The condenser was cooled by cold water at about 20 °C. The effects of tilt angle and bending position on the TCLT thermal performance characteristics were investigated. The results showed that bending and tilting TCLT would decrease thermal performance compared to the TCLT vertical orientation without bending, Qc/Q90. However, the effect of bending and tilting would be diminished as the TCLT tilted at 75 degrees at an optimum heat flux of 28.2 kW/m2.