Heat transfer and friction characteristics of spirally corrugated tubes for power plant condensers—1. Experimental investigation and performance evaluation

Abstract Heat transfer and isothermal friction pressure drop results are obtained experimentally for one smooth and 25 spirally corrugated brass tubes for power plant condenser applications. The height of the ridge is varied from 0.44 to 1.18 mm and the pitch of corrugation from 6.5 to 16.9 mm. The spiral angle of the ridge (with respect to the tube axis) is in the range 68–85 deg and the Reynolds number is in the range of 10 4 –6 × 10 4 . Heat transfer and pressure drop data are shown in forms convenient for easy comparison with those of other authors. They are used to predict theoretically Fanning friction factors and heat transfer enhancement at both sides of the tube via a unified mathematical model requiring at input the Reynolds and Prandtl numbers and the geometrical parameters of the ridge. Performance evaluation criteria are used to obtain quantitative estimates of the benefits offered by the spirally corrugated tubes.