Question

A heat exchanger uses saturated steam at 375 K to heat cold water entering at 280 K and leaving at 301 K. Only the latent heat of vaporization is removed from the steam, i.e. the steam is condensed and saturated water exits the exchanger. (a) What is the LMTD for a counter-current heat exchanger? (b) What is it for a parallel heat exchanger (c) If the counter-crrent heat exchanger has a duty(Q) of 81000 kJ/hour and an overall heat transfer coefficient (U) of 500 kJ/sq.m K, what is the calculated heat transfer area in square meters? (d) If the parallel heat exchanger has the same, what is the calculated heat transfer area in square meters?

Answer #1

A heat exchanger uses saturated steam at 375 K to heat cold
water entering at 280 K and leaving at 301 K only the latent heat
of vaporization is removed from the steam. i.e. the steam is
condensed and saturated water exit the exchanger. a) what is the
LMTD for a counter current heat exchanger? b) what is the LMTD for
a parallel or cocurrent heat exchanger? c) if the counter current
heat exchanger has a duty (Q) of 81000...

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