Aprocess fluid having a specific heat of 3500 j/kg∙k and flowing at 2 kg/s is to be cooled from 80 °c to 50 °c with chilled water, which is supplied at a temperature of 15 °c and a flow rate of 2.5 kg/s.

assuming an overall heat transfer coefficient of 2000 w/m2∙k, calculate the required heat transfer areas for the following exchanger configurations:

(a) parallel flow;

(b) counter flow;

(c) a 1-2 shell and tube exchanger with the water on the shell side.

a)

b)

c)

Explanation:

Water in:

Process fluid in:

Step 1: Determine the rate of heat transfer in the heat exchanger

Step 2: Determine outlet temperature of water

Part a) Parallel Flow

Step 3: Determine the Logarithmic Mean Temperature Difference (LMTD)

Step 4: Determine required surface area of heat exchanger

Part b) Counter Flow

Step 3: Determine the Logarithmic Mean Temperature Difference (LMTD)

Step 4: Determine required surface area of heat exchanger

Part c) 1-2 shell and tube exchanger with the water on the shell side

Step 3: Determine the Logarithmic Mean Temperature Difference (LMTD) for counter flow

Step 4: Determine LMTD Correction Factor and Corrected LMTD

Correction factor F can be determined from attached graph using P and F values calculated above

Step 5: Determine required surface area of heat exchanger

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