Question: ?A typical vertical section of a 2 3 - cm - thick and 3 - m - high wall is shown in the figure below.

?A typical vertical section of a 23-cm-thick and 3-m-high wall is shown in the figure below. The wall extends 6 ?m into the page.

The wall consists of 15-cm \times 21-cm bricks (kB = 0.81 ?W/m.K) ?separated vertically by 4-cm-thick plaster layers (kA = 0.81 ?W/m.K). ?There are also 3-cm-thick plaster layers on each side of the bricks (t1 = 3 ?cm), ?and a layer of 2-cm-thick foam (kC = 0.03 ?W/m.K) ?on the right hand side of the wall.

The inside (right) ?surface of the wall is maintained at a uniform temperature of 25\deg C (T5 = 25\deg C) ?and the convective heat transfer coefficient on the outside (left) ?surface is 15 ?W/m2.K.

The outside (left) ?temperature is 37\deg C i) ?Sketch the thermal resistance network for the wall, defining and labelling the resistances and the endpoint temperatures, T\infty and T5. ?If you have sketched this in your working solution, answer yes: Answer

?

ii) ?Write the equation for the total thermal resistance Rtotal in terms of the individual resistances. If you have written the equation in your working solution, answer yes: Answer

?

iii) ?Calculate the numerical value of each resistance, and hence the total thermal resistance. Answer

ºC/W

iii) ?Determine the total rate of heat transfer through the wall in W. ?AnswerAssume one-dimensional steady heat transfer and disregard radiation.

t1 t2 t3 2 cm Too A B C 21 cm 5

t1 t2 t3 2 cm Too A B C 21 cm 5 34 2 cm 12 Assume one-dimensional steady heat transfer and disregard radiation.

Step by Step Solution

There are 3 Steps involved in it

1 Expert Approved Answer
Step: 1 Unlock blur-text-image
Question Has Been Solved by an Expert!

Get step-by-step solutions from verified subject matter experts

Step: 2 Unlock
Step: 3 Unlock

Students Have Also Explored These Related Mechanical Engineering Questions!