### Create an Account

Home / Questions / To maximize production and minimize pumping costs crude oil is heated to reduce its viscos...

# To maximize production and minimize pumping costs crude oil is heated to reduce its viscosity during transportation from a production field a Consider a pipe in pipe configuration consisting of

To maximize production and minimize pumping costs, crude oil is heated to reduce its viscosity during transportation from a production field.

(a) 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 = 35 W/m∙ K) has an inside diameter of Di,1 = 150 mm and wall thickness ti = 10 mm while the outer steel pipe has an inside diameter of Di,2 = 250 mm and wall thickness to = ti. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (kp = 0.075 W/m∙ K) between the two pipes does not exceed its maximum service temperature of Tp,max = 70°C. The ocean water is at T∞,o = –5°C and provides an external convection heat transfer coefficient of ho = 500 W/m2 ∙ K. The convection coefficient associated with the flowing crude oil is hi = 450 W/m2 ∙ K.

(b) It is proposed to enhance the performance of the pipe-in-pipe device by replacing a thin (ta = 5 mm) section of polyurethane located at the outside of the inner pipe with an aerogel insulation material (ka = 0.012 W/m ∙ K). Determine the maximum allowable crude oil temperature to ensure maximum polyurethane temperatures are below Tp,max = 70°C.

Jun 28 2020 View more View Less