Question

Liquid A is fed to a tube of a heat exchanger and the coolant (liquid B) is fed to the shell side of the exchanger. The coolant temperature does not change because it is at its saturation temperature. Which plot best represents how the temperature of A changes with distance down the tube?

A (the highest one on top)
B (the middle linear one)
C (the concave one on the bottom)
Both B and C, depending on the physical properties of the two liquids

Answer 1

The concave cooling curve at the bottom (option C) best represents how the temperature of liquid A changes with distance down the tube in a heat exchanger.

Step-by-step explanation:

The correct answer is option C, the concave cooling curve at the bottom. In a heat exchanger, as liquid A flows down the tube, it gives off heat to the coolant (liquid B) flowing on the shell side. The temperature of liquid A will gradually decrease as it moves down the tube because heat is being transferred from it to the coolant. Since the coolant temperature remains constant at its saturation temperature, the cooling curve for liquid A will have a concave shape, gradually decreasing in temperature over time.