Hot water is transported from a cogeneration power station to commercial and industrial users through steel pipes of diameter D= 150 mm, with each pipe centered in concrete (k= 1.4 W/m-K) of square cross section (w= 300 mm). The outer surfaces of the concrete are exposed to ambient air for which T = 0°C and h = 25 W/m²-K. Concrete, k Air Water T, m (a) If the inlet temperature of water flowing through the pipe is T¡ = 90 °C, what is the heat loss per unit length of pipe in proximity to the inlet? The temperature of the pipe T¡ may be assumed to be that of the inlet water. (b) If the difference between the inlet and outlet temperatures of water flowing through a 100-m- long pipe is not to exceed 5°C, estimate the minimum allowable flow rate in . The effect of small temperature drop along the pipe on the heat rate may be ignored. The specific heat of the water is c = 4207 J/kg-K.

Hot water is transported from a cogeneration power station to commercial and industrial users through steel pipes of diameter D= 150 mm, with each pipe centered in concrete (k= 1.4 W/m-K) of square cross section (w= 300 mm). The outer surfaces of the concrete are exposed to ambient air for which T = 0°C and h = 25 W/m²-K. Concrete, k Air Water T, m (a) If the inlet temperature of water flowing through the pipe is T¡ = 90 °C, what is the heat loss per unit length of pipe in proximity to the inlet? The temperature of the pipe T¡ may be assumed to be that of the inlet water. (b) If the difference between the inlet and outlet temperatures of water flowing through a 100-m- long pipe is not to exceed 5°C, estimate the minimum allowable flow rate in . The effect of small temperature drop along the pipe on the heat rate may be ignored. The specific heat of the water is c = 4207 J/kg-K.

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.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.10P: 3.10 A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the...

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