Applied a Closed-Loop Oscillating Heat-Pipe Heat Exchanger to Increasing Oil Yield in Pyrolysis Process

Abstract

Problem statement: A Closed-Loop Oscillating Heat-Pipe (CLOHP) heat exchanger was a heat exchanger with one of the most promising conductivity capacities because of its higher cooling and condensing potential. Therefore, the aims of this study were to design and fabricate a CLOHP to be applied to increasing oil yield in the pyrolysis process. Approach: Two types of oscillating heat-pipe arrangements-parallel and perpendicular to the gas flow direction-were compared with a conventional water-to-air condenser or glass-type heat exchanger. The oscillating heat-pipe was made of four sets of copper tubes working at 90° from the horizontal plane, with an inner diameter of 2.03 mm and a total length of 18 m. The number of turns was 15. The lengths of the evaporator and condenser sections were 50 and 100 mm in total, respectively. R123 was used as a working fluid, 50% by total volume. In the experiment, an air velocity of 0.4 m sec^-1 was applied to the condenser section. 100 g of 5×5 mm pieces of motorcycle tire inner tubes were burned in a pyrolysis furnace of 500°C, having a heat-rate of 10°C min^-1. Result: The results showed that a CLOHP parallel to the gas flow direction was more effective, resulting in 39.08 g crude oil from the hot gas in the pyrolysis process and a maximum heat flux of 1,181.53 W m^-2. Conclusion: This study suggested that to improve the performance of a pyrolysis process which uses scrap motorcycle tire waste as a heating agent, a CLOHP should be placed in parallel to the gas flow line.