Abstract:
In this paper, thermal performance of a Closed Loop
Pulsating Heat Pipe (CLPHP) without insert and with insert
inside the tube has been investigated. The effect of different
parameters like working fluid, the filling ratio, inclination angle
and the input heat load on the thermal performance has been
analyzed thoroughly. In this study, CLPHP is made from long
capillary copper tubes with inner diameter of 2.0 mm and outer
diameter of 3.0 mm. The heat pipe is bent into eight U-turns and
divided into three sections: evaporator section (50 mm), adiabatic
section (120 mm) and condenser section (80 mm). Adiabatic
section is maintained by using aluminum foil surrounded by
appropriate insulation. An insert made of copper wire with
diameter 0.5mm is used throughout the tube of all three sections.
Methanol and Ethanol are used as working fluids with different
filling ratio varied from 40% to 60% in steps of 10%. The thermal
resistance has been investigated with different inclination angles
(viz. 0°, 30°, 45° and 60° from vertical) at various heat input from
10 to 100W in the steps of 10W. The result shows that, the thermal
resistance decreases as heat input increases. CLPHP with insert
structure shows better performance than the CHPHP without
insert structure particularly at 45°inclination angle. CLPHP
without insert structure shows better performance than the
CHPHP with insert structure at 00
inclinations. Methanol with
40% filling ratio and Ethanol with 60% filling ratio shows the best
performance at 0° inclination angle for CLPHP without insert
structure. CLPHP with insert structure shows better performance
than the CLPHP without insert structure at high heat input
particularly at 45°inclination angle.
