An Experimental Study of Thermal Performance of an Organic Two-Phase Closed Thermosyphon in Waste Heat Extraction.

Sultan, Gamal Ebrahim; Awad, Mohamed Mahmoud; Hegazi, Ahmed Abd-Elsalam; Elmougith, Mohamed Abdo Ahmed

doi:10.21608/bfemu.2018.95713

An Experimental Study of Thermal Performance of an Organic Two-Phase Closed Thermosyphon in Waste Heat Extraction.

Document Type : Research Studies

Authors

¹ a Professor at the Department of Mechanical Power Engineering, Mansoura University, Mansoura, Egypt

² an Associate Professor at the Department of Mechanical Power Engineering, Mansoura University, Mansoura, Egypt

³ Mechanical Engineering Department, University of Mansoura, CO 35516, Egypt

⁴ Mechanical Power department, Faculty of Engineering, Mansoura University

10.21608/bfemu.2018.95713

Abstract

Thermosyphon and passive heat exchanging devices become more popular in industrial applications due to its high capability of transferring heat with low fabrication cost. In this experiment, a thermosyphon made of copper with an internal diameter of 1.8 cm and outside diameter of 2.5 cm was investigated in recovering the wasted heat from a 4-stroke, 4-cylinder diesel engine. Waste heat from the engine comes in form of exhaust which is emitted to the atmosphere at higher temperatures. The evaporator section, which is 40 cm in length, is attached to a duct which has internal fins to guide the exhaust to take a certain path before being emitted into the atmosphere. The evaporator section was filled with various organic working fluids such as acetone, water-acetone mixture, benzene, chloroform, and petroleum ether at various filling ratios (FR) of 25%, 50%, and 100%. The condenser section was 40 cm in length, while the coolant was water passing through a cooling jacket attached to the condenser at various mass flow rates from 1 to 5 gm/sec. The experiment was taken place under three different heat input or engine speeds at 1400, 2100 and 2700 rpm. The best thermal performance of the thermosyphon results when being charged with a filling ratio FR= 50%, this agreed much with the literature reviews even when using an organic working fluid, besides, FR=25% comes in the second place and FR= 100% was the worst. Benzene (C₆H₆) showed great thermal performance over the others, acetone (C₃H₆O) comes in the second place, while the worst working fluid among others was petroleum ether (HC₃-O-CH₃). It was also found that heat exchanging process resulted in a sensible reduction of CO concentration. The maximum average reduction percentage of CO was found to be 19.33% at FR=50% benzene at engine rotational speed of 2700 rpm.

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