Liquid Freon, used to cool electronic components,

flows steadily into a horizontal tube of constant diameter, D 5

0.65 in. Heat is transferred to the flow, and the liquid boils and

leaves the tube as vapor. The effects of friction are negligible

compared with the effects of heat addition. Flow conditions

are shown. Find (a) the rate of heat transfer and (b) the

pressure difference, p1 2 p2.

1 2

Flow D = 0.65 in.

Q

•

h1 = 25 Btu/lbm

1 = 100 lbm/ft3

m = 1.85 lbm/s •

ρ

h2 = 65 Btu/lbm

2 = 0.840 lbm/ft3 ρ

P13.159