Concept explainers
Water is heated by submerging 50-mm-diameter, thin-walled copper tubes in a tank and passing hot combustion gases
If the tube surface temperature is
Want to see the full answer?
Check out a sample textbook solutionChapter 3 Solutions
Fundamentals of Heat and Mass Transfer
- A 10 ft length of pipe with an inner radius of 1 in and outer radius of 1.25 in has an outer surface temperature of 250 F. The heat transfer rate is 30,000 BTU/hr. Find the interior surface temperature. Assume k = 25 BTU/hr-ft-F.arrow_forwardConsider a copper tube with domestic hot water flowing inside (Tin =70◦C, um = 0.5m/s). The inner diameter of the tube is Din=13mm and outer diameter is Dout=15mm. The tube is located in a crawlspace and the surrounding temperature is T∞ =0 ◦C. The inner and outer heat transfer coefficients are hin = 250W/m2K and hout = 5W/m2K. The tube is insulated at the outer surface with insulating foam of thickness lf oam=17.5mm. The temperature drop of the water along the tube is 0.5◦C. 1. Draw a sketch that indicates the dimensions of the system, and the directions of heat transfer and fluid flow. 2. What is the length of the tube?arrow_forwardPart of a laboratory experiment consists of a long 4-in.-OD copper tube embedded in the center of a square insulator (asbestos with k= 0.087Btu/h-ft-°F) with 3-in. sides. The purpose of the pipe is to deliver hot water at 30 psia to the system, but the system requires that the water must not be boiling. The energy loss per foot of pipe is measured to be 35 Btu/h ft, and the outside surface temperature of the asbestos is 150°F. Assuming the water and the tube are at the same temperature, does the water boil?arrow_forward
- 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 (k, = 35 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 = 250 mm and wall thickness to = tj. Determine the maximum allowable crude oil temperature to ensure the Di,2 = 0.0425 W/m-K) between the two pipes does not exceed its maximum service = -5°C and provides an external convection heat transfer polyurethane foam insulation (kp temperature of T, р, max = 70°C. The ocean water is at T o, 0 coefficient of ho 500 W/m2.K. The convection coefficient associated with the flowing crude oil is h; = 450 W/m2-K. (2) It is proposed to enhance the performance of…arrow_forwardTo 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 (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 thickness to = tj. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (k, between the two pipes does not exceed its maximum service temperature of T, max = 70°C. The ocean water is at T , = -5°C and provides an external convection heat transfer coefficient of h, = 500 W/m2-K. The convection coefficient associated with the flowing crude oil is h¡ = 450 W/m2-K. = 0.03 W/m-K) (2) It is proposed to enhance the performance of the…arrow_forwardThe operations management of the industrial plant where you work asks you to determine the length of a 2.0 ?? diameter pipe that will be used to heat water from an inlet temperature of 20.0°C to an outlet temperature of 60.0 °C. . The operational flow of water in the pipe is to be 0.6 m/s, and the surface temperature of the wall is to be kept constant at 90.0°C by condensing steam.For the development of this task, you must obtain the properties of water at the average temperature of the fluid.To determine the forced convection heat transfer coefficient use the correlation:?? = 0.023??^0.8??^0.4arrow_forward
- 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 (k, = 40 W/m-K) has an inside diameter of D₁.I 150 mm and wall thickness t, = 20 mm while the outer steel pipe has an inside diameter of D₁,2 = 250 mm and wall thickness to = 1₁. Determine the maximum allowable crude oil temperature to ensure the polyurethane foam insulation (k, = 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 = -5°C and provides an external convection heat transfer coefficient of h, = 500 W/m².K. The convection coefficient associated with the flowing crude oil is h; = 450 W/m².K. (2) It is proposed to enhance the performance of the…arrow_forwardTo 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…arrow_forwardTo 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…arrow_forward
- 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…arrow_forward(a) A length of brass piping is 30 m long at a temperature of 18°C. When hot water flows through it the temperature of the pipe rises to 70°C. Determine the length of the hot pipe if the coefficient of linear expansion for brass is 18 x 10-6 K-¹.arrow_forwardWater (4.1 L/min) is flowing in a tube "D = 3 cm, L= 5 m" and is to be heated from 15°C to 59.8°C by applying a uniform heat flux on the outer surface of the tube by electric resistance heater. What is the power rating of the ?resistance heater (kW) If turbulent flow use Dituss- Boetler relation Nu= 0.023 Re0.8 .Prn Properties : p = 992.1 kg/m³ , C, = 4179 J/kg.°C, k 0.631 W/m°C, Pr = 4.32, v = 0.658E-6 m²/sarrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning