In: Mechanical Engineering
A double-pipe heat exchanger is designed as an engine oil cooler. The flow rate of oil is 5 kg/s, and it will be cooled from 60°C to 40°C through annulus (ID = 0.10226 m, OD = 0.1143 m). Sea water flows through the tubes (ID = 0.02664 m, OD = 0.03340 m) and is heated from 10°C to 30°C. The number of bare tubes in the annulus is 3, and the length of the hairpin is 3 m. Assume that the tube wall temperature is 35°C. Design calculations give the number of hairpins as 85. Allowable pressure drop in the heat exchanger for both streams is 20 psi. Is this design acceptable? Outline your comments.