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

Meena Meena

doi:10.3844/ajassp.2009.133.136

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.

Highlights

The CLOHP/CV is a very effective heat transfer device Akachi et al.[1]: it has a simple structure and fast thermal- response
The CLOHP/CV consists of a long capillary tube bent into many turns and the evaporator section, adiabatic section and condenser section are located at these turns, with the ends joined to form a closed loop
It was found that the CHOHP/CV is equipped with 2 check valves, as highest heat transfer

Summary

INTRODUCTION

The CLOHP/CV is a very effective heat transfer device Akachi et al.[1]: it has a simple structure and fast thermal- response. The CLOHP/CV consists of a long capillary tube bent into many turns and the evaporator section, adiabatic section and condenser section are located at these turns, with the ends joined to form a closed loop It incorporates one or more directioncontrol one-way check valves in the loop so that the working fluid can circulate in specified direction only. The principle of operation is similar to that of the CLOHP/CV are widely accepted as the most efficient heat transfer device for high heat load Akachi et al.[1] Because it incorporates one or more direction-control one-way check valves in the loop so that the working fluid can circulate in specified direction only in shown (Fig. 1a,b). The ball can move freely between the ball stopper and the valves seat in shown Fig. 2

MATERIALS AND METHODS

CONCLUSIONS