CH E 314 Quiz 1 - Winter 2017 PDF

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ChE 314 Heat Transfer Winter 2017 Quiz 1 Wednesday, Jan. 25, 1pm ETLC 1-003

Please remember to 1. Read the statement carefully, and make sure you understand what is asked 2. Provide a direct answer to the questions asked 3. Make clear schematics, diagrams, and graphs: a. arrows and dimensions must point precisely to the intended locations b. arrows and dimensions cannot finish too far or point inaccurately c. straight, parallel, and perpendicular lines must be drawn as such 4. Express the results of calculations clearly and in the units requested 5. Write clearly the steps taken in calculations or derivations. State explicitly the fundamental principles or definitions used

1.

A 200 sq. ft room needs to be cooled to 70 oF. The recommended air conditioner for this situation should absorb 9100 BTU per hour. Express conversion steps clearly. Unexplained results will not be considered 1.a

Express the target temperature in oC (4 pt.)

Answer (number and units): 1.b

Express the cooling power of the air conditioner in W (4 pt.)

Answer (number and units): 1.c

If the room is cooled at 10 oF/h, what is the cooling rate in oC per minute? (4 pt.)

Answer (number and units):

2

2.

Fill in the tables below with appropriate approximate names, units, and values suggested for use in ChE 314 (8.5 pt.)

3

3.

Steam burns can be much more severe than water burns. To compare the heat delivered by steam and by water perform the calculations stated below. Use the values on the right if needed: 3.a

Calculate in kJ the heat deposited by 10 g of liquid water cooling from 100 C to 37 C (6 pt.)

Answer (number and units): 3.b

Calculate in kJ the heat deposited by 10 g of steam condensing and cooling from 100 C to 37 C (8 pt.)

Answer (number and units):

4

4.

Determine the duty in kW of a heat exchanger in which 100 l/min of oil are cooled from 75 C to 35 C. For oil: c = 2.035 kJ/kgK, r = 865.8 kg/m3 . (6 pt.)

Answer (number and units):

5

5.

A surface of 1 m2 is at 100 C, and it is cooled by a flow of air at 0 C. The heat lost by the surface is 10 kW. Estimate the convection coefficient h in SI units. (6 pt.)

Answer (number and units):

6

LAST%NAME:% FIRST%NAME:%

ChE 314 Heat Transfer Winter 2017 Quiz 1 Wednesday, Jan. 25, 1pm ETLC 1-003

Please remember to 1. Read the statement carefully, and make sure you understand what is asked 2. Provide a direct answer to the questions asked 3. Make clear schematics, diagrams, and graphs: a. arrows and dimensions must point precisely to the intended locations b. arrows and dimensions cannot finish too far or point inaccurately c. straight, parallel, and perpendicular lines must be drawn as such 4. Express the results of calculations clearly and in the units requested 5. Write clearly the steps taken in calculations or derivations. State explicitly the fundamental principles or definitions used

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Comments( •  Must(write(equa0on(before(wri0ng(numbers( –  energy(balance,(defini0on(of(convec0on(coefficient,( etc.(

•  Must(know(name(of(constants(and(parameters( –  THERMAL(conduc0vity(

•  Must(use(proper(symbols,(unless(explained( –  q”≠q≠Q( –  ((m! ≠ m –  V ((! ≠ V...