Ethylene glycol is heated from 25°C to 40°C at a rate of 2.5 kg/s in a horizontal copper tube (k = 386 W/m·K) with an inner diameter of 2.0 cm and an outer diameter of 2.5 cm. A saturated vapor (Tg = 110°C) condenses on the outside-tube surface with the heat transfer coefficient (in kW/m2·K) given by 9.2/(Tg - Tw)0.25, where Tw is the average outside-tube wall temperature. What tube length must be used? Take the properties of ethylene glycol to be r = 1109 kg/m3, cp = 2428 J/kg·K, k = 0.253 W/m·K, m = 0.01545 kg/m·s, and Pr = 148.5.

Ethylene glycol is heated from 25°C to 40°C at a rate of 2.5 kg/s in a horizontal copper tube (k = 386 W/m·K) with an inner diameter of 2.0 cm and an outer diameter of 2.5 cm. A saturated vapor (Tg = 110°C) condenses on the outside-tube surface with the heat transfer coefficient (in kW/m2·K) given by 9.2/(Tg - Tw)0.25, where Tw is the average outside-tube wall temperature. What tube length must be used? Take the properties of ethylene glycol to be r = 1109 kg/m3, cp = 2428 J/kg·K, k = 0.253 W/m·K, m = 0.01545 kg/m·s, and Pr = 148.5.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.17P: Determine the rate of heat transfer per meter length to a light oil flowing through a 2.5-cm-ID,...

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