Effect of Evaporator Section Lengths and Working Fluids on Operational Limit of Closed Loop Oscillating Heat Pipes with Check Valves (CLOHP/CV)

Abstract

This research aims to the effect of evaporator section lengths and working fluids on operational limit of closed loop oscillating heat pipes with check valves (CLOHP/CV) with R123 Ethanol and Water were used as the working fluids. A set of CLOHP/CV was made of copper tubes in combination of following dimension: 1.77 mm inside diameter: 10 turns: 5, 10 and 15 cm equal lengths for evaporator, adiabatic and condenser sections. The working fluid was filled in the tube at the filling ratio of 50%. The evaporator section was given heat by heater while the condenser section was cooled by volume water in a cold bath. The adiabatic section was properly insulated. In the test operation. Which the temperature at the adiabatic section was controlled at 60°C in steady-state condition. From The obtained results obtained, it could be concluded as follows. When the evaporator lengths increased from 5 cm to 10 and 15 cm the critical heat transfer flux decreased. There was working fluids change from R123 to Ethanol and water the critical heat flux decreased.

Thermo-Hydrodynamic Behavior of Methanol Charged Closed Loop Pulsating Heat Pipe

“…Yang et al (2009) pointed out that increasing heat load clearly improves the thermal performance. Meena et al (2009) concluded that as working fluids change from R123 to Ethanol and water the critical heat flux decreased. The latent heat of vaporization affects the critical heat flux.…”

The Effects of Vapor Space Height on the Vapor Chamber Performance

“…Heat pipe diameter, length, material, and working fluid play important roles on heat pipe performance. Recent research on heat pipes focused more on the wick design [4], miniature pipes [5], and loop heat pipes [6][7][8]. To explore better wick structures for high-performance miniature heat pipes Lin et al [5] used the folded sheet fin to create capillary flow channels with fully and partially opened grooves made by an electric-discharge-machining technique.…”

Thermal characteristics of a resurfaced condenser and evaporator closed two-phase thermosyphon

“…The effect of evaporator length as well as working fluid on operational limit of closed loop oscillating heat pipes investigated by Meena et al [15]. They used R123, ethanol and water as working fluids at fixed filling ratio of 50%.…”