Chapt 13

Question 1

Overall heat transfer coefficient

Answer 1

U - accounts for overall resistance to transfer caused by wall [W/m^2K]

Question 2

Fudge Factor? (Fancy F)

Answer 2

_______
Delta T / Tlm [-] mean temp driving force in exchanger compared to that of countercurrent flow, which is the very best possible

Question 3

NTU?

Answer 3

Number of Transfer Units, based on a particular phase [-]

Question 4

P? (x-axis on diagrams)

Answer 4

delta Ti / delta Tmax. Temp change of phase i compared to max possible temp change [-]

Question 5

•
q ?

Answer 5

Rate of heat gain by a phase [W]

Question 6

Q

Answer 6

Heat lost or gained by a fluid up to a given point in the exchanger [J/kg of one of the phases]

Question 7

R? (y-axis on diagrams)

Answer 7

Ratio of temp changes or heat flows of the fluid [-]

Question 8

Tlm?

Answer 8

Log mean temperature driving force [K]

Question 9

delta Tmax

Answer 9

Max temp difference between phases [K]

Question 10

•
M, C,T?

Answer 10

Refer to shell-side flow rate, specific heat, and temp

Question 11

•
m, c, t?

Answer 11

Refer to tube-side flow rate, specific heat, and temp

Question 12

ņ

Answer 12

Efficiency of heat removal

Question 13

Counter and Co-current flow heat transfer

Answer 13

• • •
qleaving gas = qentering liquid = qtransferred

Question 14

equation for • ?
q

Answer 14

q = (U)(A)(deltaTlm)

Question 15

delta Tlm?

Answer 15

(delta T2 - delta T1) / ln( delta T2 / delta T1)

Question 16

Efficiency equation?

Answer 16

nl = deltaT1 /deltaTmax. {deltaT1 = Tl, out - Tl, in}