Consider a 1.2-m-high and 2-m-wide glass window (refer to the Figure) whose thickness is 6 mm and thermal conductivity is k= 0.78 W/m K. The room is maintained at 24°C while the temperature of the outdoors is -5°C. The convection heat transfer coefficients on the inner and outer surfaces of the window to be h1 = 10 W/m- K and h2 = 25 W/m- K. Disregarding any heat transfer by radiation and using the themal-resistance concept, determine (a) the steady rate of heat transfer through this glass window and (b) the temperature of its inner surface (T;). Glass 24°C T1 -5 °C. L=6 mm

Consider a 1.2-m-high and 2-m-wide glass window (refer to the Figure) whose thickness is 6 mm and thermal conductivity is k= 0.78 W/m K. The room is maintained at 24°C while the temperature of the outdoors is -5°C. The convection heat transfer coefficients on the inner and outer surfaces of the window to be h1 = 10 W/m- K and h2 = 25 W/m- K. Disregarding any heat transfer by radiation and using the themal-resistance concept, determine (a) the steady rate of heat transfer through this glass window and (b) the temperature of its inner surface (T;). Glass 24°C T1 -5 °C. L=6 mm

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.

Chapter3: Transient Heat Conduction

Section: Chapter Questions

Problem 3.16P: 3.16 A large, 2.54-cm.-thick copper plate is placed between two air streams. The heat transfer...

See similar textbooks

Similar questions

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.
heat transfer course Consider a large plate as given in the figure below. The thermal conductivity and thickness of the plate are 0,55 W/m.K and 3,915 mm. What is the surface temperature (Ts) of the plate in K for given properties?
3-19 Consider a 1.2-m-high and 2-m-wide double-pane win- dow consisting of two 3-mm-thick layers of glass (k = 0.78 W/m . °C) separated by a 12-mm-wide stagnant air space (k = 0.026 W/m. °C). Determine the steady rate of heat transfer through this double-pane window and the temperature of its inner surface for a day during which the room is maintained at 24°C while the temperature of the outdoors is -5°C. Take the convection heat transfer coefficients on the inner and outer Glass 3 12 3 mm Frame FIGURE P3-19 = surfaces of the window to be h₁ = 10 W/m² °C and h₂ 25 W/m². °C, and disregard any heat transfer by radiation.
(1) The temperature of inner surface of insulation wall is t,=100°C, while the outer surface releases the heat by convection to surroundings air with temperature of -20°C. The thickness of the insulating layer is 5 cm and its thermal conductivity of 0,05 W/(m-K). What is the value of heat transfer coefficient on the outside this wall if its surface temperature t, is of 0°C.
Q2/ A 3-m internal diameter spherical tank made of 2-cm-thick stataless steel (k= 15 W/m 0°C. The tank is located in a room whose %3D C) is used to store iced water at Te temperature is T-22°C. The walls of the room are also at 22°C. The outer surface of the tank is black 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 h-80 W/m2 C and h 10 W/m2 C, respectively. 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.
200 W/m K, but the thermal conductivity of Rod 2, 3-130 Two very long, slender rods of the same diameter and length are given. One rod (Rod 1) is made of aluminum and has a thermal conductivity k k2, is not known. To determine the thermal conductivity of Rod 2, both rods at one end are thermally attached to a metal surface which is maintained at a constant temperature Th Both rods are losing heat by convection, with a convection heat transfer coefficient h into the ambient air at Teg. The surface temperature of each rod is measured at various distances from the hot base surface. The measurements = 40 cm from the base is the same as that of the rod of unknown thermal conductivity (Rod 2) at x2 = 20 cm from the base. Determine the reveal that the temperature of the aluminum rod (Rod 1) at X thermal conductivity k2 of the second rod (W/m K) FIGURE P3-130 k=200 W/m K Rod 1 1= 40 cm т, Tа) h, T Rod 2 2= 20 cm T2(x
A large concrete wall is 300 mm thick and has a thermal conductivity of 1.2 W/m C. The heat flux through the wall is 100 W/m2. The higher-temperature surface of the wall is at 42 C. What is the temperature of the other surface of the wall?
A 2x2-m glass window, 1 cm thick is subjected to 10°C and 3°C inner and outer temperatures respectively. If the thermal conductivity of the glass is 0.78 W/m-°C, what is the amount of heat loss, in kl, through the glass over a period of 5 hours?
HEAT TRANSFER Question-1: A long aluminum cylinder with a diameter of 5 cm is initially at a temperature of 2000C and is suddenly exposed to a 700C convection environment and becomes h = 525W / m20C. Find the 1.25 cm diameter temperature and the heat loss per unit length 1 minute after the cylinder is subjected to convection. Thermal properties of the material k = 215 W / moC
1/ The roof of an electrically heated home is 6 m long, 8 m wide, and 0.25 m thick, and is made of a flat layer of concrete whose thermal conductivity is k = 0.8 W/m.°C (Figure. 1-3). The temperatures of the inner and the outer surfaces of the roof one night are measured to be 15°C and 4°C, respectively, for a period of 10 hours. Determine the rate of heat loss through the roof at night
A cylindrical storage tank with diameter of 4m and a length of 10 m will hold a fluid whose temperature must be maintained at 347k. in order to size the heater required for the tank the following worst-case scenario is considered: Ambient temperature=-20 wind speed=20m/s tank wall temperature=347k what size (kW) heater will be needed?
Convection - Heat Transfer Coefficient (HTC) (1) The temperature of inner surface of insulation wall is t,=100°C, while the outer surface releases the heat by convection to surroundings air with temperature of -20°C. The thickness of the insulating layer is 5 cm and its thermal conductivity of 0,05 W/(m-K). What is the value of heat transfer coefficient on the outside this wall if its surface temperature t, is of 0°C.