Question

A heat exchanger uses oil
(c_{p} = 1880 J kg^{-1} K^{-1}) at an
initial temperature of 205°C to heat up water with heat capacity of
1 kcal kg^{-1} K^{-1}, and density = 0.998 g
cm^{-3}, flowing at 0.00376 m^{3} min^{-1}
from 16°C to 44°C. The configuration of the heat exchanger is in
countercurrent. The oil mass flow rate is 270 kg
h^{-1}.

(1 cal = 4.18 J)

(i) What is the heat
transfer area required for an overall heat transfer coefficient of
0.34 kW m^{-2} K^{-1})?

(ii) Determine the number of transfer units (NTU).

(iii) Calculate the effectiveness of the heat exchanger.

Answer #1

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