Two concentric spheres with diameters of 5 cm and 10 cm are having the surface temperatures maintained at 200°C and 100°C, respectively. The enclosure between the two concentric spherical surfaces is filled with nitrogen gas at 1 atm. If both concentric sphere surfaces are black (« = 1), determine the rate of heat transfer on the inner surface.

Two concentric spheres with diameters of 5 cm and 10 cm are having the surface temperatures maintained at 200°C and 100°C, respectively. The enclosure between the two concentric spherical surfaces is filled with nitrogen gas at 1 atm. If both concentric sphere surfaces are black (« = 1), determine the rate of heat transfer on the inner surface.

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.

Chapter11: Heat Transfer By Radiation

Section: Chapter Questions

Problem 11.32P

See similar textbooks

Similar questions

Two very large walls are at constant temperature of 463oF and 887 oF. Assuming that the walls behave like black bodies, how much heat in Btu/hr-ft2 must be removed from the colder wall in order to maintain a constant pressure (σ=0.1714x10-8 Btu/hr-ft2-R)
A 2-m-internal-diameter double-walled spherical tank is used to store iced water at 0°C. Each wall is 0.5 cm thick, and the 1.5-cm-thick air space between the two walls of the tank is evacuated in order to minimize heat transfer. The surfaces surrounding the evacuated space are polished so that each surface has an emissivity of 0.15. The temperature of the outer wall of the tank is measured to be 20°C. Assuming the inner wall of the steel tank to be at 0°C, determine (a) the rate of heat transfer to the iced water in the tank and (b) the amount of ice at 0°C that melts during a 24-h period.
Consider steady heat transfer between two large parallel plates at constant temperatures T1 = 300 K and T2 = 200 K that are L = 1 cm apart, as shown below. Assuming the surface to be black, determine the rate of heat transfer between the plates per unit surface area assuming the gap between the plates is free flowing air with h = 7.5 W/m2oC
A 1.2 m wide and 5.1 m long solar collector is mounted to a roof. Now the average surface temperature of the solar collector is measured to be 50 oC. The effective surrounding sky temperature is 8 oC. If the emissivity of the collector is 0.88, determine the rate of heat transfer from the collector to the surroundings due to radiation.
A hot water heater 150 mm wide, 2 m long and 1 m hight is at a surface temperature of 50°C in the surroundings of 20°C. The heat transfer coefficient for convection is given by h = 1.31(AT)1/3 where h is in W/m²K and AT is in K. Take the emissivity of the heater as 0.95 and assume that it is completely surrounded by black surroundings. Take o as 5.67 x 10-8 W/m²K4. The total rate of heat flux from the heater is W/m². [Rounded upto two decimal places]
A circular ceramic plate that can be modeled as a blackbody is being heated by an electrical heater. The plate is 30 cm in diameter and is situated in a surrounding ambient temperature of 15°C where the natural convection heat transfer coefficient is 12 W/m2?K. If the efficiency of the electrical heater to transfer heat to the plate is 80%, determine the electric power that the heater needs to keep the surface temperature of the plate at 200°C.
A 5-in-diameter spherical ball is known to emit radiation at a rate of 550 Btu/h when its surface temperature is 950 R. Determine the average emissivity of the ball at this temperature.
Two infinite black plates at 500°C and 100°C exchange heat by radiation. If another perfectly black plate is placed between the 500°Cand 100°C plates, what is the temperature of the center plate? K
A 2-m-diameter thin-walled stainless steel spherical tank is filled with chemicals undergoing a reaction. The reaction releases heat through the tank, where the tank outer surface temperature is 50°C and is exposed to air at 20°C. The stainless steel surface of the tank has an emissivity of 0.35. Determine the rate of heat release from the chemical reaction inside the tank. Is the given emissivity value reasonable for a stainless steel surface? What is the contribution of natural convection to the overall rate of heat loss at the tank surface?
Assuming the sun to be a black body emitting radiation with maximum intensity at 1 = 0.48u m, determine the following: (i) The surface temperature of the sun, and (ii) The heat flux at surface of the sun.
An oil radiator has an outside surface area of 0.18 m2 and operates at a surface temperature of 85 degree Celsius. If the oil radiator behaves as a black body and the Stefan-Boltzmann constant value is equal to 5.67 X 10-8 W/(m²-K4), calculate the radiation heat flux at the surface of the radiator. O 0.53 W/m² O 2.96 W/m² O 167.64 W/m² O 931.35 W/m²
A 5-m-internal-diameter spherical tank made of 1.5-cm-thick stainless steel (k = 15 W/m-°C) is used to store iced water at 0°C. The tank is located in a room whose temperature is 30°C. The walls of the room are also at 30°C. The outer surface of the tank is gray (emissivity = 0.9), and heat transfer between the outer surface of the tank and the surroundings is by natural convection and radiation. The convection heat transfer coefficients at the inner and the outer surfaces of the tank are 80 W/m²-°C and 10 W/m²-°C, respectively. Determine the amount of ice at 0°C that melts during a 24-h period. The heat of fusion of water at atmospheric pressure is hfg = 333.7 kJ/kg.\ ANSWER:_____kg