Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
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
Textbook Question
Chapter 1, Problem 1.10P
A freezer compartment consists of a cubical cavity that is 2 mon a side. Assume the bottom to be perfectlyinsulated. What is the minimum thickness of styrofoaminsulation
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solutionStudents have asked these similar questions
A 1 in. o.d. (outer diameter) tube reactor is insulated with a 3 inch layer of asbestos. If the temperature of the outer surface of the insulation is 100 °F and the rate of heat loss per foot of reactor length is 50 BTU/hr, what must the temperature of the inside of the reactor be? [for asbestos, k = 0.105 BTU/hr ft °F]
In order to reduce the heat loss through a large
furnace wall, the decision has been made to add
external insulation. Calculate the thickness of insulation
required to reduce the heat loss by 75%.
Before the change is made, no outer steel shell is used.Data: Refractory brick and wall brick:k = 0.87 W m-1 K-1Insulation: k = 0.090 W m-1 K-1•Steel: k = 43 W m-1 K-1h = 55 W m-1 K-1 (inside furnace).h = 11 W m-1 K-1 (outside furnace).
A brick wall, plastered on one face, has a thermal conductance of 0.36 m2 K/W, an inside surface resistance of 0.4 m2K/W, and an outside surface resistance of 0.075 m2K/W. Calculate the total heat resistance.
Chapter 1 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 1 - The thermal conductivity of a sheet of rigid,...Ch. 1 - The heat flux that is applied to the left face of...Ch. 1 - A concrete wall, which has a surface area of 20m2...Ch. 1 - The concrete slab of a basement is 11 in long. 8...Ch. 1 - Consider Figure 1.3. The heat flux in the...Ch. 1 - The heal flux through a wood slab 50 mm thick,...Ch. 1 - The inner and outer surface temperatures of a...Ch. 1 - A thermodynamic analysis of a proposed Brayton...Ch. 1 - A glass window of width W=1m and height H=2m is 5...Ch. 1 - A freezer compartment consists of a cubical cavity...
Ch. 1 - The heat flux that is applied to one face of a...Ch. 1 - An inexpensive food and beverage container is...Ch. 1 - What is the thickness required of a masonry wall...Ch. 1 - A wall is made from an inhomogeneous...Ch. 1 - The 5-mm-thick bottom of a 200-mm-diameter panmay...Ch. 1 - A square silicon chip (k=150W/mK) is of width...Ch. 1 - For a boiling process such as shown in Figure 1.5...Ch. 1 - You’ve experienced convection cooling if you’ve...Ch. 1 - Air at 40°C flows over a long, 25-mm-diameter...Ch. 1 - A wall has inner and outer surface temperatures of...Ch. 1 - An electric resistance heater is embedded in a...Ch. 1 - The free convection heat transfer coefficient on a...Ch. 1 - A transmission case measures W=0.30m on a sideand...Ch. 1 - A cartridge electrical heater is shaped as a...Ch. 1 - A common procedure for measuring the velocity of...Ch. 1 - A square isothermal chip is of width w=5mm on...Ch. 1 - The temperature controller for a clothes dryer...Ch. 1 - An overhead 25-m-long, uninsulated industrial...Ch. 1 - Under conditions for which the same room...Ch. 1 - A spherical interplanetary probe of 0.5-m diameter...Ch. 1 - An instrumentation package has a spherical outer...Ch. 1 - Consider the conditions of Problem 1.22. However,...Ch. 1 - If TsTsur in Equation 1.9, the radiation heat...Ch. 1 - A vacuum system, as used ¡n sputtering...Ch. 1 - An electrical resistor is connected to a battery,...Ch. 1 - Pressurized water (pin=10bar,Tin=110C) enters...Ch. 1 - Consider the tube and inlet conditions of Problem...Ch. 1 - An internally reversible refrigerator has a...Ch. 1 - A household refrigerator operates with cold-...Ch. 1 - Chips of width L=15mm on a side are mounted to...Ch. 1 - Consider the transmission case of Problem 1...Ch. 1 - One method for growing thin silicon sheets for...Ch. 1 - Heat is transferred by radiation and convection...Ch. 1 - Radioactive wastes are packed in a long,...Ch. 1 - An aluminum plate 4 mm thick is mounted in a...Ch. 1 - A blood warmer is to be used during the...Ch. 1 - Consider a carton of milk that is refrigerated at...Ch. 1 - Prob. 1.48PCh. 1 - Liquid oxygen, which has a boiling into of 90 K...Ch. 1 - The emissivity of galvanized steel sheet, a...Ch. 1 - Three electric resistance heaters of length...Ch. 1 - A hair dryer may be idealized as a circular duct...Ch. 1 - In one stage of an annealing process, 304...Ch. 1 - Convection ovens operate on the principle of...Ch. 1 - Annealing, an important step ¡n semiconductor...Ch. 1 - In the thermal processing of semiconductor...Ch. 1 - A furnace tor processing semiconductor materials...Ch. 1 - Prob. 1.58PCh. 1 - Consider the wind turbine of Example 1.3. To...Ch. 1 - Consider the conducting rod of Example 1.4...Ch. 1 - A long bus bar (cylindrical rod used for making...Ch. 1 - A 50mm45mm20mm cell phone chargerhas a surface...Ch. 1 - A spherical, stainless steel (AISI 302) canister...Ch. 1 - A freezer compartment is covered with a...Ch. 1 - A vertical slab of Wood’s metal is joined to a...Ch. 1 - A photovoltaic panel of dimension 2m4m isinstalled...Ch. 1 - Following the hot vacuum forming of a...Ch. 1 - Prob. 1.69PCh. 1 - A computer consists of an array of five printed...Ch. 1 - Prob. 1.71PCh. 1 - The roof of a car in a parking lot absorbs a solar...Ch. 1 - Consider the conditions of Problem 1.22,but the...Ch. 1 - Most of the energy we consume as food ¡s converted...Ch. 1 - Prob. 1.75PCh. 1 - The wall of an oven used to cure plastic parts is...Ch. 1 - An experiment to determine the convection...Ch. 1 - A thin electrical heating element provides a...Ch. 1 - A rectangular forced air healing duct is suspended...Ch. 1 - Consider the steam pipe of Example 1.2. The...Ch. 1 - During its manufacture, plate glass at 600°C is...Ch. 1 - The curing press of Example 1.9 involves exposure...Ch. 1 - The diameter and surface emissivity of an...Ch. 1 - Prob. 1.84PCh. 1 - A solar flux of 700W/m2K is incident on a...Ch. 1 - In considering the following problems involving...
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
- 1.1 On a cold winter day, the outer surface of a 0.2-m-thick concrete wall of a warehouse is exposed to temperature of –5°C, while the inner surface is kept at 20°C. The thermal conductivity of the concrete is 1.2 W/m K. Determine the heat loss through the wall, which is 10-m long and 3-m high. Problem 1.1arrow_forwardA 1.0-mm-diameter wire is maintained at a temperature of 400°C and exposed to aconvection environment at 40·C with h=120 W/㎡2.C. Calculate the thermal conductivitythat will just cause an insulation thickness of 0.2 mm to produce a “critical radius."How much of this insulation must be added to reduce the heat transfer by 75 percent from thatwhich would be experienced by the bare wire?arrow_forwardA thick-walled tube of stainless steel (L = 0.50 m; k = 21.63 W/m-K) with an inside diameter of 0.0254 m and outside diameter of 0.0508 m, is covered with an insulation (∆x =0.0254 m) with k = 0.2423 W/m-K. If the inside wall temperature of the pipe is at 400 oC, calculate the temperature at the interface between the metal and the insulation (in oC) if the outside surface of the insulation is at 29.8 oC. 99 K in Pa.arrow_forward
- A 1.0-mm-diameter wire is maintained at a temperature of 400 •C and exposed to a convection environment at 40 •C with h = 120 W/m2 • -C. Calculate the thermal conductivity in BTU/hr-ft-deg F that will just cause an insulation thickness of 0.2 mm to produce a "critical radius."arrow_forwardA dormitory at a large university, built 50 years ago, has exterior walls constructed of Ls= 25-mm-thick sheathing with a thermal conductivity of ks= 0.1 W/m·K. To reduce heat losses in the winter, the university decides to encapsulate the entire dormitory by applying an Li= 25-mm-thick layer of extruded insulation characterized by ki= 0.029 W/m·K to the exterior of the original sheathing. The extruded insulation is, in turn, covered with an Lg= 5-mm-thick architectural glass with kg= 1.4 W/m·K. Determine the heat flux through the original and retrofitted walls when the interior and exterior air temperatures are T∞,i= 22°C and T∞,o= -2.5°C, respectively. The inner and outer convection heat transfer coefficients are hi= 5 W/m2·K and ho= 25 W/m2·K, respectively. a. what is the heat flux through the original walls in W / m^2 b. what is the heat flux through the retrofitted wall in W / m^2arrow_forwardA dormitory at a large university, built 50 years ago, has exterior walls constructed of Ls = 32-mm-thick sheathing with a thermal conductivity of ks = 0.2 W/m · K. To reduce heat losses in the winter, the university decides to encapsulate the entire dormitory by applying an Li = 35-mm-thick layer of extruded insulation characterized by ki = 0.021 W/m · K to the exterior of the original sheathing. The extruded insulation is, in turn, covered with an Lg = 5-mm-thick architectural glass with kg = 1.1 W/m · K. Determine the heat flux through the original and retrofitted walls when the interior and exterior air temperatures are T∞,i = 20°C and T∞,o = -5°C, respectively. The inner and outer convection heat transfer coefficients are hi = 6 W/m2 · K and ho = 27 W/m2 · K, respectivelyarrow_forward
- Additional insulation is added with thermal conductivity of 0.015 W/mK maintaining the outer side temperature at 30 C. How thick is the added insulation in mm if heat transmission is reduced by half ?arrow_forwardConsider a 0.6 m X 0.6 m epoxy laminate (k = 0.2 W/m-k) whose thickness is 5 mm. In order to reduce the thermal resistance across the thickness, cylindrical copper fillings (k = 380 W/m-k) of 2 mm diameter are evenly implanted in throughout the laminate with a spacing of 6 mm (center to center) between the fillings. a) Determine the thermal resistance of the laminate with and without the copper fillings. b) Assuming the temperature difference across the laminate is 20°C, calculate the total heat transfer rates with and without the fillings.arrow_forwardA hot steam pipe having an inside surface temperature of 250°C has an inside diameter of 8 cm and a wall thickness of 5.5 mm. It is covered with a 9-cm layer of insulation having k =0.5 W/m-°C, followed by a 4-cm layer of insulation having k =0.25W/m-°C. The outside temperature of the insulation is 20°C. Calculate the heat lost per meter of length. Assume k =47 W/m-°C for the pipe.arrow_forward
- The heat conducts through the shape below. The temperature of the right face is 93 °C, while the left face is at 23 °C. If the top and bottom faces are completely insulated, and the thermal conductivity of the material decreases with decreasing temperature. * Assume that the thermal conductivity is 100 at 23, decreased to 10 at 93. A) Sketch the temperature profile inside the plate. B) If both sides of the plate in the above problem is exposed to air: Left side (h = 20 W/m2K, TL = 20 °C) and right side (h = 90 W/m2K). Calculate the temperature of the air on the right side.arrow_forwardA wall 2 cm thick is to be constructed from material that has an average thermal conductivity of 1.3 W/m. °C . The wall is to be insulated with material having an average thermal conductivity of 0.35 W/m. °C, so that the heat loss per square meter will not exceed 1830 W. Assuming that the inner and outer surface temperatures of the insulated wall are 1300 and 30 degrees * C , calculate the thickness of insulation required.arrow_forwardRequired info: There is a 2.00 cm thick stagnant air pocket. a) What thickness of cork would have the same R-factor as the stagnant air pocket? The thermal conductivity of air is 0.0230 W/m-K and of cork is 0.0460 W/m-K. b) What thickness of tin would be required for the same R-factor as a 2.00-cm-thick stagnant air pocket? The thermal conductivity of air is 0.0230 W/m:K and of tin is 66.8 W/m-K. THANK Uarrow_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
Understanding Conduction and the Heat Equation; Author: The Efficient Engineer;https://www.youtube.com/watch?v=6jQsLAqrZGQ;License: Standard youtube license