= 16 W/m.K. The inner diameter and thickness of the pipe are 26 cm and 1 cn espectively. The surrounding temperature is 28 °C. The convective heat transfe oefficient at the steam side and the outside of the pipe is 90 W/m?.K and 1 N/m².K, respectively. Derive an expression for the temperature profile across th ipe thickness as a function of the radial position r.

= 16 W/m.K. The inner diameter and thickness of the pipe are 26 cm and 1 cn espectively. The surrounding temperature is 28 °C. The convective heat transfe oefficient at the steam side and the outside of the pipe is 90 W/m?.K and 1 N/m².K, respectively. Derive an expression for the temperature profile across th ipe thickness as a function of the radial position r.

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.

Chapter4: Numerical Analysis Of Heat Conduction

Section: Chapter Questions

Problem 4.51P

See similar textbooks

Similar questions

Estimate the rate of heat loss per unit length from a 5-cm ID, 6-cm OD steel pipe covered with high-temperature insulation having a thermal conductivity of 0.11 W/(m K) and a thickness of 1.2 cm. Steam flows in the pipe. It has a quality of 99% and is at 150C. The unit thermal resistance at the inner wall is 0.0026(m2K)/W the heat transfer coefficient at the outer surface is 17W/(m2K) and the ambient temperature is 16C.
3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer coefficient on one side is and on the other side is . If the temperature of both streams is suddenly changed from 38°C to 93°C, determine how long it takes for the copper plate to reach a temperature of 82°C.
The handle of a ladle used for pouring molten lead is 30 cm long. Originally the handle was made of 1.9cm1.25cm mild steel bar stock. To reduce the grip temperature, it is proposed to form the handle of tubing 0.15 cm thick to the same rectangular shape. If the average heat transfer coefficient over the handle surface is 14 W/m K, estimate the reduction of the temperature at the grip in air at 21C.
An electronic device that internally generates 600 mW of heat has a maximum permissible operating temperature of 70C. It is to be cooled in 25C air by attaching aluminum fins with a total surface area of 12cm2. The convection heat transfer coefficient between the fins and the air is 20W/m2K. Estimate the operating temperature when the fins are attached in such a way that (a) there is a contact resistance of approximately 50 K/W between the surface of the device and the fin array and (b) there is no contact resistance (in this case, the construction of the device is more expensive). Comment on the design options.
2.7 A very thin silicon chip is bonded to a 6-mm thick aluminum substrate by a 0.02-mm thick epoxy glue. Both surfaces of this chip-aluminum system are cooled by air at , where the convective heat transfer coefficient of air flow is . If the heat dissipation per unit area from the chip is under steady-state conditions, draw the thermal circuit for the system and determine the operating temperature of the chip.
2.38 The addition of aluminum fins has been suggested to increase the rate of heat dissipation from one side of an electronic device 1 m wide and 1 m tall. The fins are to be rectangular in cross section, 2.5 cm long and 0.25 cm thick, as shown in the figure. There are to be 100 fins per meter. The convection heat transfer coefficient, both for the wall and the fins, is estimated to be K. With this information determine the percent increase in the rate of heat transfer of the finned wall compared to the bare wall.
Steam in a heating system flows through tubeswhose outer diameter is 5 cm and whose walls are maintainedat a temperature of 180°C. Circular aluminum alloy 2024-T6fins (k = 186 W/m·K) of outer diameter 6 cm and constantthickness 1 mm are attached to the tube. The space betweenthe fins is 3 mm, and thus there are 250 fins per meter lengthof the tube. Heat is transferred to the surrounding air at T` = 25°C, with a heat transfer coefficient of 40 W/m2·K. Determine the increase in heat transfer from the tube per meter of its length as a result of adding fins.
The flow of water entering a pipe is 0.25 kg / s and its temperature is 20 ° C. The diameter of the pipe is 20 mm and the wall temperature of the pipe is 100 ° C. If the average value of the heat transfer coefficient is 700 W / m C, what is the length of the pipe required to raise the water temperature to 80 ° C?
A 10-cm diameter pipe is covered by 2 layers of lagging. The insidelayer is 4 cm thick and has a coefficient of thermal conductivity of 0.08W/m-K. The outside layer is 3cm thick and has a coefficient of thermalconductivity of 0.15 W/m-K. The steam main conveys steam apressure of 1.7 MPa with 25 C superheat. The outside temperature ofthe lagging is 27 C. If the steam main is 30 m long, determine theinterface temperature of the lagging and overall coefficient of heattransfer based on outside area.
Solve for this: Steam at 200°C flows in a stainless steel pipe (k = 15 W/m·K) whose inner and outer diameters are 5.5 cm and 6 cm. The pipe is covered with 3-cm-thick insulation (k = 0.038 W/m·K). Heat is lost to thesurroundings at 7°C by convection, with a convection heat transfer coefficient of 24 W/m2·K. Taking the heat transfer coefficient inside the pipe to be 70 W/m2·K, determine the rate of heat loss from the steamper unit length of the pipe. Also determine the temperature drops across the pipe shell and the insulation
A hot-water pipe (k = 50 W/m K) for house heating in winter season, made of 3/4-inch schedule 40 pipe (OD = 25.5 mm; thickness = 2.0 mm) is 10 meters long and contains water at 60 C. The air around the pipe is at 20C. The heat transfer coefficient inside and outside the pipe are 1,120 W/m2 K and 15 W/m2 K, respectively. Insulation with thermal conductivity of 20 W/m K is to be added to the pipe. Determine the heat loss from the pipe due to insulation of 120 mm thick.
Heat Transfer Course Copper balls with an initial temperature of 200 degrees centigrade(ρ = 8933 kg / m3, k = 401 W / m oC, cp = 385 J / kg oC, α = 1.166 * 10-4 m2 / s) in air at 30 degrees centigrade 2 it is allowed to cool down for a period of minutes. Since the balls are 2 cm in diameter and the heat transfer coefficient is 80 W / m2 oC,a) What is the temperature of the balls at the end of the cooling process?b) If 1000 balls per hour are left to be cooled, what is the total heat transfer from the balls to the air?