Focus of research findings presented at ACRA in Xi’an

Smaller diameter copper tubes are gradually replacing copper tubes of diameter 7 mm and more owing to the possibility of reducing the use of materials and refrigerant volumes. Announcing this, the International Copper Association (ICA), an organisation for promoting the use of copper worldwide, explained that the experiments were performed at the Institute of Refrigeration and Cryogenics at Shanghai Jiao Tong University (SJTU).

The new research work on smaller diameter copper tubes was presented at the Sixth Asian Conference on Refrigeration and Air Conditioning (ACRA) in Xi’an, China, held from August 26 to 28, ICA said, and elucidated the finer points of the research: The heat transfer characteristics of a round-tube, plate fin coils with 5 mm copper tubes and the effects of fin pitch, fin size and inlet relative humidity were measured on 11 different coils. It was found that the effects were more obvious for coils with tube diameters of 5 mm compared to coils with tube diameters of 7 mm or more. Fin efficiencies were calculated for partially wet fins as well as for fully wet fins and a correlation was developed to predict the air-side heat transfer of a fin-and-tube heat exchanger coil, and the correlation agreed well with the experiments.

In a related news release, ICA reiterated that there was a renewed interest in copper as a coil material for ACR products. Confirming this and speaking on behalf of MicroGroove, Nigel Cotton said, “It’s an exciting time for researchers to work on new eco-friendly core designs, made possible by MicroGroove copper tubes.”