To maximize production and minimize pumping costs, crude oil is heated to reduce its viscosity during transportation from a production field. (1) Consider a pipe-in-pipe configuration consisting of concentric steel tubes with an intervening insulating material. The inner tube is used to transport warm crude oil through cold ocean water. The inner steel pipe ( ks = 40 W/m-K) has an inside diameter of Di, 1 = 150 mm and wall thickness t; = 20 mm while the outer steel pipe has an inside diameter of D2 = 250 mm and wall thickness, = 1,. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (k, = 0.0425 W/m.K) between the two pipes does not exceed its maximum service temperature of Tp, max = 70°C. The ocean water is at Too, o ho T = -5°C and provides an external convection heat transfer coefficient of h = 500 W/m²K. The convection coefficient associated with the flowing crude oil is h₁ = 450 W/m²K. (2) It is proposed to enhance the performance of the pipe-in-pipe device by replacing a thin (t = 10 mm) section of polyurethane located at the outside of the inner pipe with an aerogel insulation material (k = 0.012 W/m-K). Determine the maximum allowable crude oil temperature to ensure maximum polyurethane temperatures are below T p. max=70°C. Physical Properties Mathematical Functions Step 1 Determine the convection heat transfer resistance on the inside of the pipe per unit length, in m·K/W. R' 1,conv.i i m-K/W Save for Later Step 2 Attempts: unlimited Submit Answer Determine the conduction resistance of the polyurethane per unit length without the aerogel, in m·K/W. R' 1,cond,p = i m-K/W Step 3 Determine the conduction resistance of the polyurethane per unit length when aerogel is used, in m·K/W. R' t,cond,p,ae Save for Later Step 4 m.K/W Attempts: unlimited Submit Answer Determine the maximum crude oil temperature if no aerogel is used, in °C. T∞ = i Save for Later Step 5 °C Attempts: unlimited Submit Answer Determine the maximum crude oil temperature if aerogel is used, in °C. Too, ae i eTextbook and Media °C Save for Later

To maximize production and minimize pumping costs, crude oil is heated to reduce its viscosity during transportation from a production field. (1) Consider a pipe-in-pipe configuration consisting of concentric steel tubes with an intervening insulating material. The inner tube is used to transport warm crude oil through cold ocean water. The inner steel pipe ( ks = 40 W/m-K) has an inside diameter of Di, 1 = 150 mm and wall thickness t; = 20 mm while the outer steel pipe has an inside diameter of D2 = 250 mm and wall thickness, = 1,. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (k, = 0.0425 W/m.K) between the two pipes does not exceed its maximum service temperature of Tp, max = 70°C. The ocean water is at Too, o ho T = -5°C and provides an external convection heat transfer coefficient of h = 500 W/m²K. The convection coefficient associated with the flowing crude oil is h₁ = 450 W/m²K. (2) It is proposed to enhance the performance of the pipe-in-pipe device by replacing a thin (t = 10 mm) section of polyurethane located at the outside of the inner pipe with an aerogel insulation material (k = 0.012 W/m-K). Determine the maximum allowable crude oil temperature to ensure maximum polyurethane temperatures are below T p. max=70°C. Physical Properties Mathematical Functions Step 1 Determine the convection heat transfer resistance on the inside of the pipe per unit length, in m·K/W. R' 1,conv.i i m-K/W Save for Later Step 2 Attempts: unlimited Submit Answer Determine the conduction resistance of the polyurethane per unit length without the aerogel, in m·K/W. R' 1,cond,p = i m-K/W Step 3 Determine the conduction resistance of the polyurethane per unit length when aerogel is used, in m·K/W. R' t,cond,p,ae Save for Later Step 4 m.K/W Attempts: unlimited Submit Answer Determine the maximum crude oil temperature if no aerogel is used, in °C. T∞ = i Save for Later Step 5 °C Attempts: unlimited Submit Answer Determine the maximum crude oil temperature if aerogel is used, in °C. Too, ae i eTextbook and Media °C Save for Later

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.

Chapter9: Heat Transfer With Phase Change

Section: Chapter Questions

Problem 9.4DP

See similar textbooks