Determine the conduction resistance of the polyurethane per unit length without the aerogel, in m-K/W.R'1.cond.pm-K/WDetermine the conduction resistance of the polyurethane per unit length when aerogel is used, in m-K/W.R' t.cond.p.aem-K/WiDetermine the maximum crude oil temperature if no aerogel is used, in °C.T =°CDetermine the maximum crude oil temperature if aerogel is used, in °C.T ae =i°C To maximize production and minimize pumping costs, crude oil is heated to reduce its viscosity during transportation from aproduction field.(1) Consider a pipe-in-pipe configuration consisting of concentric steel tubes with an intervening insulating material. The inner tube isused to transport warm crude oil through cold ocean water. The inner steel pipe (k, = 45 W/m-K) has an inside diameter of D;, 1 =150 mm and wall thickness t; = 20 mm while the outer steel pipe has an inside diameter of D;, 2 = 250 mm and wall thicknesst, = t;. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (kp = 0.03 W/m-K)between the two pipes does not exceed its maximum service temperature of T, max = 70°C. The ocean water is at T,o = -5°C andprovides an external convection heat transfer coefficient of h, = 500 W/m²-K. The convection coefficient associated with theflowing crude oil is hị = 450 W/m²-K.(2) It is proposed to enhance the performance of the pipe-in-pipe device by replacing a thin (ta = 10 mm) section of polyurethanelocated at the outside of the inner pipe with an aerogel insulation material (k, = 0.012 W/m-K). Determine the maximum allowablecrude oil temperature to ensure maximum polyurethane temperatures are below T, max= 70°C.

Answered: Image /qna-images/answer/a6317077-2bf0-4ffb-b6f7-28523cdc05ad.jpg

Determine the conduction resistance of the polyurethane per unit length without the aerogel, in m-K/W. R' 1,condp m-K/W Determine the conduction resistance of the polyurethane per unit length when aerogel is used, in m-K/W R' t.cond.p.ae m-K/W Determine the maximum crude oil temperature if no aerogel is used, in °C. i °C Determine the maximum crude oil temperature if aerogel is used, in °C. T, ae °C i

Determine the conduction resistance of the polyurethane per unit length without the aerogel, in m-K/W. R' 1,condp m-K/W Determine the conduction resistance of the polyurethane per unit length when aerogel is used, in m-K/W R' t.cond.p.ae m-K/W Determine the maximum crude oil temperature if no aerogel is used, in °C. i °C Determine the maximum crude oil temperature if aerogel is used, in °C. T, ae °C i

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 7.37P

See similar textbooks

Similar questions

7.43 Liquid sodium is to be heated from 500 K to 600 K by passing it at a flow rate of 5.0 kg/s through a 5-cmID tube whose surface is maintained at 620 K. What length of tube is required?
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 ti = 20 mm while the outer steel pipe has an inside diameter of Di,1 = 250 mm and wall thickness . Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation ( kp = 0.0425 W/m·K) 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. (2) It is proposed to enhance the performance of the pipe-in-pipe device by replacing a thin ( ta =10 mm) section of polyurethane located at the outside of the inner pipe with an…
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 ti= 20 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= 0.0675 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. (2) It is proposed to enhance the performance of the…
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 ti= 20 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= 0.0675 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. (2) It is proposed to enhance the performance of the…
A transformer is to be cooled via forced air convection. To increase the effectiveness of thecooling, Alloy 1095 cast aluminum fins are attached to the top of the transformer overwhich air is blown (negligible thermal contact resistance between the transformer and thefins). The fins are 2 cm thick and 7 cm long and span the entire length of the transformer,and the transformer is 7 cm wide and 10 cm long. Air leaves the cooling fan at 25°C .a) Decide how to model the fins before performing any real analysis. Youare willing to accept some error in your analysis and so you will either model thefins as having adiabatic tips or being infinitely long. You expect the average convectioncoefficient over the heat transfer surfaces for this system to be around 50 W m2– K⁄ .Which tip condition should you use for the fins in your analysis? b) Modeling the transformer as being isothermal, determine the average convectioncoefficient over the heat transfer surfaces. Account for heat transfer from the…
Natural convection heat coefficient for vertical stainless pipe, outer diameter 100 mm, length 0.25 m. The pipe surface temperature is 125 ° C, and the air temperature is 30 ° C. Convection coefficient = Answer W / m² ° C.
Fins, or extended surfaces, commonly are used in a variety of engineering applications to enhance cooling. Common examples include a motorcycle engine head, a lawn mower engine head, extended surfaces used in electronic equipment, and finned tube heat exchangers in room heating and cooling applications. Consider aluminum fins of a rectangular profile, which are used to remove heat from a surface whose temperature is100° C . The temperature of the ambient air is 20° C. We are interested in determining how the temperature of the fin varies along its length and plotting this temperature variation. For long fins, the temperaturedistribution along the fin is given by
Calculate the heat losses per unit length in a horizontal tube with an outside diameter of 15 cm, if its surface is kept at 400 K AND the surrounding air has a temperature of 300 K and a pressure of 1 bar.The properties of air at a pressure of 1 bar and a film temperature of 350 K are: In this case, v = 20.76 x 10-6 m2/s , α = 0.2983 x 10-4 m2/s, k = 0.03003 W/mK, Pr = 0.697, β = 2.86 x 10-3 K-1
4.) A 15-cm-diameter steam line carries saturated steam at 6 MPa and is located in a tunnel with stagnant air with a temperature of 50oC. The outside unit convective coefficient is 8.5 W/m2-K. The steam line is covered with 3 cm of 85% magnesia insulation. It is decided to reduce the heat loss by one-half. How much 85% magnesia insulation is required? Neglect thermal resistance of pipe and inside surface.
Plot how hx (heat transfer coefficient) depends on the distance along a plate (x) and explain how this relationship .
Based on the picture above, make a schematic and determine the average temperature difference over the entire length of the tube (ATLM). (value 25)
A long steel rod 0.305 m in diameter is initially at a temperature of 588 K. It is immersed in an oil bath maintained at 311 K. The surface convective coefficient is 125 W/m2 -K. Calculate the temperature at the center of the rod after 1 h. The average physical properties of the steel are k = 38 W/m-K and α = 0.0381 m2/h.