# Distilled water is being cooled by a 20% propylene glycol solution in a 1-1/U counter flow plate and

Distilled water is being
cooled by a 20% propylene glycol solution in a 1-1/U counter flow plate and
frame heat exchanger. The water enters the heat exchanger at 50°F at a flow
rate of 86,000 lbm/h. For safety reasons, the water outlet temperature should
never be colder than 35°F. The propylene glycol solution enters the heat
exchanger at 28°F with a flow rate of 73,000 lbm/h. The port distances on the
heat exchanger are Lv = 35 in and Lh = 18 in. The plate width is Lw = 21.5 in. The
plate thickness is 0.04 in with a plate pitch of 0.12 in. The chevron angle is
30° and the plate enlargement

Distilled water is being
cooled by a 20% propylene glycol solution in a 1-1/U counter flow plate and
frame heat exchanger. The water enters the heat exchanger at 50°F at a flow
rate of 86,000 lbm/h. For safety reasons, the water outlet temperature should
never be colder than 35°F. The propylene glycol solution enters the heat
exchanger at 28°F with a flow rate of 73,000 lbm/h. The port distances on the
heat exchanger are Lv = 35 in and Lh = 18 in. The plate width is Lw = 21.5 in. The
plate thickness is 0.04 in with a plate pitch of 0.12 in. The chevron angle is
30° and the plate enlargement factor is 1.17. All ports have a 2 in diameter.
The fouling factor of the propylene glycol solution can be estimated as 2 × 10_5

h-ft2- ° F/ B t u .

a. Determine the maximum
number of plates the heat exchanger can have while ensuring that the water
outlet temperature never drops below 35°F.

b. Determine the thermal
and hydraulic performance of the heat exchanger with the specified number of
plates. Summarize your findings in a table similar.