| With the requirement of manufacture and science technology in recent years, thetechnique of enhancing heat transfer has been developed greatly, and has been widely used inmany areas such as oil, chemistry, dynamic and refrigeration, and so on. It can improve heattransfer performance by improving heat exchanger’s structure, and that is effective measurefor full using of energy and energy-saving reduction.By experimental study, this paper studied the heat transfer efficiency of vertical groundheat exchanger among three tubes. It is concluded that rifled tube can enhance heat transferby increasing area. It is concluded as follows.(1) Temperature trends of export water in rifled tube and smooth type is basically same,and export water temperature is increased with time increasing. in the same velocity, waterflow through the smooth tube and rifled tube of the same length, temperature difference ofimport and export in rifled tube is greater than the smooth tube.(2) When Water inlet temperatureater is35℃, the average water temperature differenceof import and export of rifled tube about15mm is high0.49℃than smooth tube, and theaverage water temperature difference of import and export of rifled tube about10mm is high0.63℃than smooth tube, and the average water temperature difference of import and export ofrifled tube about10mm is high0.14℃than rifled tube of15mm.(3) When Water inlet temperatureater is50℃, the average water temperature differenceof import and export of rifled tube about15mm is high0.93℃than smooth tube, and theaverage water temperature difference of import and export of rifled tube about10mm is high1.16℃than smooth tube, and the average water temperature difference of import and export ofrifled tube about10mm is high0.23℃than rifled tube of15mm.(4) In0h to48h, export water temperature of the two rifled tube and smooth type all lower quickly, but in48h to96h, export water temperature of the two rifled tube and smoothtype relatively lower slowly. |
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