Elements Of Electromagnetics
7th Edition
ISBN: 9780190698614
Author: Sadiku, Matthew N. O.
Publisher: Oxford University Press
expand_more
expand_more
format_list_bulleted
Concept explainers
Question
Lagged and unlagged pipes
Hot water at 160 ⁰C is passing through a pipe, and it is lagged with a plastic covering. The coefficient of thermal conduction of the plastic is 0.2 Wm-1K-1 and the heat transfer coefficient is 16 Wm-2K-1. The ambient temperature surrounding the pipe is 25 ⁰C. Determine the critical radius and hence the maximum heat loss. Calculate the heat loss for varying thicknesses of lagging and plot this against the thickness. From the graph, estimate an optimal thickness of lagging and explain your reasons. You can use Excel for the calculations and plotting.
Expert Solution
This question has been solved!
Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.
Step by stepSolved in 4 steps with 2 images
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
- A w=40 mm square computer CPU is air cooled with fans shown in the figure below. The surrounding air in the case has convection coefficient h = 100 W/m2⋅K and temperature T∞ = 30oC. If the aluminum heat sink (k = 230 W/m⋅K) on your computer has N = 20 exposed equally-spaced rectangular fins of thickness t =1 mm and length Lf = 15 mm: a) Calculate the overall efficiency ηo of the fins b) Given that the CPU is generating QCPU = 90 W, determine the temperature of the CPU, assuming the CPU is a uniform temperature and well-insulated on its sides. Ignore thermal contact resistance and fin array base resistancearrow_forward1. Calculate the overall heat-transfer coefficient (U=?) for a frame construction wall made of brick veneer (120-lbm/ft³) with 3-in. fiberglass insulation bats between the 2x4 wood studs (softwood) that are 16-in. on center. The wind velocity is 15-mph. Fill out the table below also utilizing materials data from the textbook. Also, calculate the total heat loss if the referenced wall was 9-ft tall and 35-ft in length set in Ohio, Clevland @ 99% winter OAT with an indoor setpoint of 75°F. Hint: 2x4 wood studs are 16-in. on center and 2-in. thick by 4-in. deep thus the empty space between each stud is 14-in. Remember use R = L/K & R = 1/C for materials. Between Frame (R-Value) At Framing (R-Value) Outside Surface 4-in. Face Brick (k=middle value) 1/2-in. Sheathing reg. density 3-in. Insulation Batt 2"x4" Wood Studs (k=middle value) 1/2-in. Gypsum Board Inside Surface Total (R-Value): ● U = ● Q= Btu/(hr-ft²-F) Btu/h Heat Lossarrow_forwardA gas at 525 ° C flows through an AISI 316 stainless steel pipe (d.i = 94 mm and d.o. = 100 mm). The pipe is covered with a covering of mineral wool granules with 35 mm thick asbestos binders. The pipe is exposed to ambient air at 25 ° C. The heat transfer coefficients for the surrounding gas and air are 29 W / (m2 K) and 12W / (m2 K), respectively. Do the following: (a) Draw a schematic diagram and the thermal resistances of the scheme b) Calculate the critical radius and indicate if the coating increases or decreases heat transfer c) Calculate the heat loss per meter of tube length with the covering. d) Estimate the temperature on the surface of the coating exposed to the environmentarrow_forward
- To cool hot oil, an engineer has suggested that the oil be pumped through a pipe submerged in a nearby lake. The pipe (external diameter = 15 cm) will be placed in the horizontal direction. The temperature of the outer surface of the pipe averages 125 ° C. The surrounding water temperature is assumed to be constant at 15 ° C. Pipe length 125 m. If it is assumed that there is no water movement. a. Determine the convective heat transfer coefficient of the outer pipe surface to the water. = Answer Watt / (m² ° C) b. Determine the heat transfer rate from the pipe to the water. = Answer kWarrow_forwardFind the heat flow rate through the composite wall as shown in the following figure. Assume one dimensional flow and take k 1 = 150 W/m degree, k 2 = 30 W/m degree, k 3 = 65 W/m degree, k 4 = 50 W/m degree. AB = 3 cm, BC = 8 cm and CD = 5 cm. The distance between middle horizontal line from the top is 3 cm and from the bottom is 7 cm.arrow_forward
arrow_back_ios
arrow_forward_ios
Recommended textbooks for you
- Elements Of ElectromagneticsMechanical EngineeringISBN:9780190698614Author:Sadiku, Matthew N. O.Publisher:Oxford University PressMechanics of Materials (10th Edition)Mechanical EngineeringISBN:9780134319650Author:Russell C. HibbelerPublisher:PEARSONThermodynamics: An Engineering ApproachMechanical EngineeringISBN:9781259822674Author:Yunus A. Cengel Dr., Michael A. BolesPublisher:McGraw-Hill Education
- Control Systems EngineeringMechanical EngineeringISBN:9781118170519Author:Norman S. NisePublisher:WILEYMechanics of Materials (MindTap Course List)Mechanical EngineeringISBN:9781337093347Author:Barry J. Goodno, James M. GerePublisher:Cengage LearningEngineering Mechanics: StaticsMechanical EngineeringISBN:9781118807330Author:James L. Meriam, L. G. Kraige, J. N. BoltonPublisher:WILEY
Elements Of Electromagnetics
Mechanical Engineering
ISBN:9780190698614
Author:Sadiku, Matthew N. O.
Publisher:Oxford University Press
Mechanics of Materials (10th Edition)
Mechanical Engineering
ISBN:9780134319650
Author:Russell C. Hibbeler
Publisher:PEARSON
Thermodynamics: An Engineering Approach
Mechanical Engineering
ISBN:9781259822674
Author:Yunus A. Cengel Dr., Michael A. Boles
Publisher:McGraw-Hill Education
Control Systems Engineering
Mechanical Engineering
ISBN:9781118170519
Author:Norman S. Nise
Publisher:WILEY
Mechanics of Materials (MindTap Course List)
Mechanical Engineering
ISBN:9781337093347
Author:Barry J. Goodno, James M. Gere
Publisher:Cengage Learning
Engineering Mechanics: Statics
Mechanical Engineering
ISBN:9781118807330
Author:James L. Meriam, L. G. Kraige, J. N. Bolton
Publisher:WILEY