1. The wall of a refrigerated van is made of steel sheet, glass wool and plywood....
Fantastic news! We've Found the answer you've been seeking!
Question:
Transcribed Image Text:
1. The wall of a refrigerated van is made of steel sheet, glass wool and plywood. The outer surface is made up of Ls = 5mm steel sheet (Ks=25 W/mK) and the inner surface is made up of Lp=15mm plywood (Kp=0.05 W/mK). Glass wool (LG=25mm, KG=0.01 W/mK) is placed between the inner and outer surface. The temperature of the cold environment inside the van is Ti=-20C, while the outside surface is exposed to To=-30C. The average values of convective heat transfer coefficients at the inner and outer surfaces of the wall are 12 W/mK and 20 W/mK respectively. The surface area of the wall is 0.85m. Determine (a) The individual components of the thermal resistance to heat flow (b) The rate of heat flow through the wall. (c) The temperatures at (i) the outer surface of the wall, (ii) the interface between steel sheet and glass wool, (ii) the interface between glass wool and plywood, and (iv) the inner surface of the wall (40 Points) Ta Steel sheet Glass wool Plywood kp kG ks T Fluid film at the outer surface Fluid film at the inner surface 2. A 1.5m long electrical resistance wire with diameter 4mm has a measured voltage drop of 25V for a current flow of 40A. The thermal conductivity of the wire material is 24 W/(m.K). Determine (a) the rate of generation of thermal energy per unit volume within the wire (b) the maximum temperature in the wire if the surface temperature is kept at 600K. (30 Points) 3. A 2m high and 1m wide plate with thickness 0.3m has one of its sides maintained at 450K while the other is maintained at 350K. The thermal conductivity of the plate can be assumed to vary linearly in that temperature range as K(T) = K(1+ T) where Ko= 18W/mK and = 8.7X104 K-. Assuming 1-dimensional heat transfer and no edge effect, determine the rate of heat conduction through the plate. (30 points) 1. The wall of a refrigerated van is made of steel sheet, glass wool and plywood. The outer surface is made up of Ls = 5mm steel sheet (Ks=25 W/mK) and the inner surface is made up of Lp=15mm plywood (Kp=0.05 W/mK). Glass wool (LG=25mm, KG=0.01 W/mK) is placed between the inner and outer surface. The temperature of the cold environment inside the van is Ti=-20C, while the outside surface is exposed to To=-30C. The average values of convective heat transfer coefficients at the inner and outer surfaces of the wall are 12 W/mK and 20 W/mK respectively. The surface area of the wall is 0.85m. Determine (a) The individual components of the thermal resistance to heat flow (b) The rate of heat flow through the wall. (c) The temperatures at (i) the outer surface of the wall, (ii) the interface between steel sheet and glass wool, (ii) the interface between glass wool and plywood, and (iv) the inner surface of the wall (40 Points) Ta Steel sheet Glass wool Plywood kp kG ks T Fluid film at the outer surface Fluid film at the inner surface 2. A 1.5m long electrical resistance wire with diameter 4mm has a measured voltage drop of 25V for a current flow of 40A. The thermal conductivity of the wire material is 24 W/(m.K). Determine (a) the rate of generation of thermal energy per unit volume within the wire (b) the maximum temperature in the wire if the surface temperature is kept at 600K. (30 Points) 3. A 2m high and 1m wide plate with thickness 0.3m has one of its sides maintained at 450K while the other is maintained at 350K. The thermal conductivity of the plate can be assumed to vary linearly in that temperature range as K(T) = K(1+ T) where Ko= 18W/mK and = 8.7X104 K-. Assuming 1-dimensional heat transfer and no edge effect, determine the rate of heat conduction through the plate. (30 points)
Expert Answer:
Related Book For
Fundamentals of Thermal-Fluid Sciences
ISBN: 978-0078027680
5th edition
Authors: Yunus A. Cengel, Robert H. Turner, John M. Cimbala
Posted Date:
Students also viewed these mechanical engineering questions
-
With statistics often times probabilities are reported, but the general audience has little understanding of the construct of those probabilities or what they mean in a real-world application, is...
-
Which marketing communication tool is most effective between Daraz and Pickaboo e commerce site and why?Make a list describing all the different marketing communication tools in detail you see being...
-
2. Steam power plant (a) The boiler of a power plant operates at a maximum temperature of 750oC. The condenser of the power plant draws in cooling water at 20oC. What is the theoretical maximum...
-
Jake needed a summer job and was lucky enough to land a position as a ticket collector at a local amusement park. On his first day, he was assigned to work alongside Tim who had worked at the park...
-
Explain the difference between the "nature-of-expense" and "function of expense" classifications.
-
In Problems 3558, graph each function using transformations or the method of key points. Be sure to label key points and show at least two cycles. Use the graph to determine the domain and the range...
-
Your family shares the cooking duties in the home. You've agreed to prepare the meal every 5 days. The last time you prepared dinner was a Tuesday. What day of the week will it be after you've...
-
An automatic lathe produces rollers for roller bearings, and the process is monitored by statistical process control charts. The central line of the chart for the sample means is set at 8.50 and for...
-
I need help . Full answer and Solution please PLAYING THE ACCOUNTING EQUATION 1. Naruto Uzumaki is an owner of Konoha Enterprises, a sole proprietorship. The company's total assets is PhP...
-
Idexo Corporation is a privately held designer and manufacturer of licensed college apparel in Cincinnati, Ohio. In late 2019, after several years of lackluster performance, the firms owner and...
-
id gender 1 Male age 3 No 2 Male 58 Yes 3 Female 4 Female 8 No 70 Yes 5 Male 14 No 6 Female 47 Yes 7 Female 52 Yes SOLOOOOO married hypertens heart_dise occupation residence metric_1 metric_2 metric...
-
1. Ideal Gas Tables 2. Nitrogen is heated from 300 K to 1100 K. Assume that during this process the pressure dropped from 200 to 150 kPa. Calculate the change in Entropy per Kilogram. Using: Using...
-
Name the polynomial expression below. 10u - 8 Select an answer Select an answer Question Help: Video Message instructor Post to forum Submit Question
-
Evaluate each expression. (Simplify your answers completely.) (a) 43.4 X (b) 94.9-2 X Simplify by evaluating exponents. (c) (22)3
-
A city's electricity consumption, E, in gigawatt-hours per year, is given by E = 0.22p, where p is the price in dollars per kilowatt- hour charged. What does the solution to the equation 0.22p = 5...
-
Presentation Technology and Politics In class work (group) and presentation (graded) I. Introduction A. Definition of technology and politics (from sources in Moodle readings) -in text B. Importance...
-
How should Aspen ski resort account for the free skiing given to employees on their days off?
-
What steps must a business take to implement a program of social responsibility?
-
Consider the flow of saturated steam at 270.1 kPa that flows through the shell side of a shell-and-tube heat exchanger while the water flows through 4 tubes of diameter 1.25 cm at a rate of 0.25 kg/s...
-
Repeat Prob. 2028 assuming the circuit board to be positioned horizontally with (a) chips facing up and (b) chips facing down. Repeat Prob. 2028 A 50-cm 50-cm circuit board that contains 121 square...
-
Using a timer (or watch) and a thermometer, conduct the following experiment to determine the rate of heat gain of your refrigerator. First make sure that the door of the refrigerator is not opened...
-
A Mrs T Hulley is paid monthly. For part of April 19X6 she earns 860 and then goes on maternity leave, her maternity pay for April being 90. She has pay free of tax 320, whilst on the next 250 she...
-
A P Urmston is paid monthly. For June 19X6 he earns 1,500 and also receives statutory sick pay of 150. He pays 90 superannuation which is allowed as a relief against income tax and he has further...
-
The data which follows was extracted from the books of account of H Kirk, an engineer, on 31 March 19X6, his financial year end. You are required to allocate each or part of the items above to either...
Study smarter with the SolutionInn App