Heat Transfer Experiments and Analyses on Double-Tube Bundle Heat Exchanger

Experiments were performed on the double-tube bundle heat exchanger. The hot side of the heat exchanger consists of parallel flow channels of the inner tubes and the space between the shell and the double-tube bundle, and the cold side is the narrow annular flow channels between the inner and outer tubes. The test fluid in both hot and cold sides is de-ionized water. The heat-transfer coefficients were obtained from the experiment in the range of Reynolds number from 2000 to 38000. The detached coefficients method was used in the absence of direct measurement of the tube temperature. It is found that the ranges of laminar flow in both internal and external flow passages are wider than regular circular tube. The heat transfer coefficient of internal side is lower than those from Dittus-Boelter formula, while the heat transfer coefficient of external side in this experiment is higher than that for the corrugated pipe. The heat transfer coefficient of the narrow annular channel is significantly determined by its structure.