Introduction to Heat Transfer
6th Edition
ISBN: 9780470501962
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Concept explainers
Videos
Textbook Question
Chapter 4, Problem 4.20P
A furnace of cubical shape, with external dimensions of0.35 m, is constructed from a refractory brick (fireclay).If the wall thickness is 50 mm, the inner surface temperatureis
Expert Solution & Answer
Trending nowThis is a popular solution!
Students have asked these similar questions
c) A steel pipe of 100 mm bore, and 10 mm bore thickness, carrying dry saturated steam at 28
bars, is insulated with a 40 mm layer of moulded insulation. This insulation in turn is
insulated with a 60 mm layer of felt. The atmospheric temperature is 15 °C.
Calculate:
(i) the rate of heat loss by the steam per metre pipe length.
(ii) the temperature of the outside
Dimensions in mm
surface.zzzzzzz
h₂-15 W/m²K
Steel
k₁=50 W/mK
AVALEHT
Ø100
1₂
"
Steam 28 bar
h-550 W/m²K,
Inner heat transfer coefficient = 550 W/m² K
Outer heat transfer coefficient = 15 W/m² K
Thermal conductivity of steel = 50 W/m K
Thermal conductivity of felt = 0.07 W/m K
Moulded
insulation
Felt
Moulded insulation
K₂=0.09 W/mK
Thermal conductivity of moulded insulation = 0.09 W/m
40
10.
A
60
15°C
Felt
K₁=0.07 W/mK
zzzzzzzz
The Diamond Ring Solution. The processing chip on the computer that controls the navigation equipment on your spacecraft is
overheating. Unless you fix the problem, the chip will be damaged and the navigation system will shut down. You open the panel and
find that the small copper disk that was supposed to bridge the gap between the smooth top of the chip and the cooling plate is
missing, leaving a 2.0 mm gap between them. In this configuration, the heat cannot escape the chip at the required rate. You notice by
the thin smudge of thermal grease (a highly thermally conductive material used to promote good thermal contact between surfaces)
that the missing copper disk was 2.0 mm thick and had a diameter of 1.0 cm. You know that the chip is designed to run below 70 °C, and
the copper cooling plate is held at a constant 5.0 °C.
(a) What was the rate of heat flow from the chip to the copper plate when the original copper disk was in place and the chip was at its
maximum operating…
Question(2): The ceiling outer surface temperature of an oven is 60°C. If the oven is in an
environment of 20 °C and the ceiling is 1 m wide and 2 m long. find the heat loss from the
furnace ceiling surface.
NOTE: Use the physical properties of the air at 40°C for the environment.
Chapter 4 Solutions
Introduction to Heat Transfer
Ch. 4 - In the method of separation of variables (Section...Ch. 4 - A two-dimensional rectangular plate is subjected...Ch. 4 - Consider the two-dimensional rectangular plate...Ch. 4 - A two-dimensional rectangular plate is subjected...Ch. 4 - Prob. 4.5PCh. 4 - Prob. 4.6PCh. 4 - Free convection heat transfer is sometimes...Ch. 4 - Prob. 4.8PCh. 4 - Radioactive wastes are temporarily stored in a...Ch. 4 - Based on the dimensionless conduction heat rates...
Ch. 4 - Prob. 4.11PCh. 4 - A two-dimensional object is subjected to...Ch. 4 - Prob. 4.13PCh. 4 - Two parallel pipelines spaced 0.5 m apart are...Ch. 4 - A small water droplet of diameter D=100m and...Ch. 4 - Prob. 4.16PCh. 4 - Pressurized steam at 450 K flows through a long,...Ch. 4 - Prob. 4.19PCh. 4 - A furnace of cubical shape, with external...Ch. 4 - Prob. 4.21PCh. 4 - Prob. 4.22PCh. 4 - A pipeline, used for the transport of crude oil,...Ch. 4 - A long power transmission cable is buried at a...Ch. 4 - Prob. 4.25PCh. 4 - A cubical glass melting furnace has exterior...Ch. 4 - Prob. 4.27PCh. 4 - An aluminum heat sink k=240W/mK, used to coolan...Ch. 4 - Hot water is transported from a cogeneration power...Ch. 4 - Prob. 4.30PCh. 4 - Prob. 4.31PCh. 4 - Prob. 4.32PCh. 4 - An igloo is built in the shape of a hemisphere,...Ch. 4 - Consider the thin integrated circuit (chip) of...Ch. 4 - Prob. 4.35PCh. 4 - The elemental unit of an air heater consists of a...Ch. 4 - Prob. 4.37PCh. 4 - Prob. 4.38PCh. 4 - Prob. 4.39PCh. 4 - Prob. 4.40PCh. 4 - Prob. 4.41PCh. 4 - Determine expressions for...Ch. 4 - Prob. 4.43PCh. 4 - Prob. 4.44PCh. 4 - Prob. 4.45PCh. 4 - Derive the nodal finite-difference equations for...Ch. 4 - Prob. 4.47PCh. 4 - Prob. 4.48PCh. 4 - Consider a one-dimensional fin of uniform...Ch. 4 - Prob. 4.50PCh. 4 - Prob. 4.52PCh. 4 - Prob. 4.53PCh. 4 - Prob. 4.54PCh. 4 - Prob. 4.55PCh. 4 - Prob. 4.56PCh. 4 - Steady-state temperatures at selected nodal points...Ch. 4 - Prob. 4.58PCh. 4 - Prob. 4.60PCh. 4 - The steady-state temperatures C associated with...Ch. 4 - A steady-state, finite-difference analysis has...Ch. 4 - Prob. 4.64PCh. 4 - Consider a long bar of square cross section (0.8 m...Ch. 4 - Prob. 4.66PCh. 4 - Prob. 4.67PCh. 4 - Prob. 4.68PCh. 4 - Prob. 4.69PCh. 4 - Consider Problem 4.69. An engineer desires to...Ch. 4 - Consider using the experimental methodology of...Ch. 4 - Prob. 4.72PCh. 4 - Prob. 4.73PCh. 4 - Prob. 4.74PCh. 4 - Prob. 4.75PCh. 4 - Prob. 4.76PCh. 4 - Prob. 4.77PCh. 4 - Prob. 4.78PCh. 4 - Prob. 4.79PCh. 4 - Prob. 4.80PCh. 4 - Spheres A and B arc initially at 800 K, and they...Ch. 4 - Spheres of 40-mm diameter heated to a uniform...Ch. 4 - To determine which parts of a spiders brain are...Ch. 4 - Prob. 4.84P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- An oil storage tank has 20mm steel walls covered with 50mm of fiber glass insulation. if the oil temperature is kept at 150 degree Celsius, what is the rate of heat loss when the outside temperature is 20 degree Celsius and external air coefficient is 20W/m². How much would the heat loss be reduced by doubling the thickness of the insulation?arrow_forward5. A horizontal disc of 9 cm diameter, which is at a temperature of 45°C, is immersed facing upward in a pool of 25°C water. Calculate the total heat transfer from the surface to the water.arrow_forwardA-For a general office room, the exposed wall (with a window, outside winter type) construction is 19 mm plaster outside (cement and sand) and 20 cm brick (building). The area of the window is 50% of the exposed wall. Calculate the heating load required for the office caused by the wall and window. Take Tout-5 °C and Tin-25 °C, exposed wall height=3 m and width=5 m, Inside and outside still air thermal resistance fi= 9.37 W/m²°C and fo= 34.1 W/m2 °C respectively. (6 marks)arrow_forward
- Problem 1 A hot water pipe is used for domestic applications is insulated with a layer of calcium silicate. If the insulation is 25 mm thick and its inner and outer surfaces are maintained at Ts,1 = 800 K and Ts,2 = 400 K, respectively. The outside diameter is 0.12 m. Given the thermal conductivity calcium silicate insulation equals to 0.09 W/m.K. A. Define the difference between lagged and unlagged pipes. B. Calculate the heat loss per unit length for this pipe.arrow_forwardA cold storage room has a wall consists of an inside finish of 0.60 in cement plaster(k = 0.67), two layers of corkboard each 2.5 in thick (k = 0.03) and an outside layer of building tile. The value of U for the entire wall is 0.058, the internal air filmcoefficient is 1.65, the inner temperature is 23°F and the outside temperature is85°F. Calculate the heat flow through the unit wall area, Btu/hr.ft2A. 1.47 B. 2.47 C. 3.47 D. 4.47arrow_forwardDetermine the heat flux through the composite walls as shown in Figure. The frontal area (normal to heat flow) for the layers of Fir brick and Brick is 1 sq.m. The frontal area for Asbestos and Earth layers are equal and the summation of the frontal areas of them is 1 sq.m. as shown required to answer. OPTIONS: 1.Heat flux is around 487.3 Watt 2.Heat flux is around 742.7 Watt 3.Heat flux is around 305.4 Watt 4.Nonearrow_forward
- 1. A composite furnace wall is made up of a 12-in. lining of magnesite refractory brick, a 5-in.thickness of 85% magnesia, and a steel casing 0.10-in. thick. Flue gas temperature is 2200 F andthe boiler room is at 80 F. Gas side film coefficient is 15 Btu/hr-sq.ft-F and air side is 4.0.Determine:a. The thermal current Q/Ab. Interface temperaturesc. Effect on thermal current and inside refractory wall temperature if the magnesia insulation weredoubled.arrow_forwardHi, kindly solve this problem and show the solution. Thank youarrow_forwardA composite wall is composed of 8 in. of fire-clay brick, 6 in. of chrome brick, and4 in. of common brick. The inside wall surface temperature is 2000"F, and the outsidesurface temperature is 300"F. Determine (a) the heat loss per ft2 of wall area; (b) thetemperatures at the brick interfaces; (c) the temperature 8 in. in from the outer surface.arrow_forward
- An underwater sonar that maps the ocean bathymetry is encapsulated in a sphere with a diameter of 85 mm. During operation, the sonar generates heat at a rate of 300W. What is the sonar surface temperature when it’s located in a water column where the temperature is 15o C and the water current is 1 m/sec? The sonar was pulled out of the water without turning it off, thus, it was still working. The air temperature was 15o C and the air speed was 3 m/sec. What was the sonar surface temperature? Was there any reason for concern?arrow_forwardAn eyed plate & pin is assembled as illustrated and are subjected to an opposing force of 10KN. The rod diameter & plate thickness is 6mm. The width of the plate is 20mm. A hole to which the pin is inserted is 8mm in diameter is located at the center of the plate. The plate is made of annealed SAE 1025 & the pin is high-heat oil quenched SAE 1095. (a) Determine if the assembly is safe to use; otherwise (b) Determine the safe load of the assembly.arrow_forwardA composite wall is formed of a 2.5 cm copper plate, a 3.2 mm layer of asbestos,and a 5 cm layer of fiberglass. The wall is subjected to an overall temperaturedifference of 560oC. Calculate the heat flux through the composite structure.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
First Law of Thermodynamics, Basic Introduction - Internal Energy, Heat and Work - Chemistry; Author: The Organic Chemistry Tutor;https://www.youtube.com/watch?v=NyOYW07-L5g;License: Standard youtube license