Open AccessImprovement of Thermal Performance of Coiled Tube Heat Exchanger Utilizing Air Bubble Injection Technique
Author(s) -
Saif Salah Hasan,
Ali Shakir Baqir,
Hameed B. Mahood
Publication year - 2021
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/877/1/012040
Subject(s) - heat exchanger , materials science , shell and tube heat exchanger , plate heat exchanger , mechanics , thermodynamics , thermocouple , concentric tube heat exchanger , heat transfer , airflow , thermal , heat spreader , composite material , physics
The heat transfer enhancement in terms of temperature of a vertical helically coiled tube heat exchanger is carried out experimentally. The experiments were achieved in a heat exchanger with a 50 cm height and 15 cm internal diameter under four different cold and three hot water mass flow rates and four different airflow rates. At the same time, the temperature difference was taken invariant (ΔT=20°C). To avoid some uncertainties, the hot side temperature of the heat exchanger was measured via k-type thermocouples. The results showed that the increase of air injection flow rate improved heat transfer from the hot stream flowing in the coil to the shell’s cold stream. An intimate thermal mixing when air injected is clearly observed, which could be responsible for the heat exchanger’s thermal enhancement. Finally, the injected air pressure was noticed to be having only a minor effect on thermal performance improvement.