DieselShip's Online Content Library

Q1. An annular cooling water jacket surrounds a 75 mm mean diameter pipe carrying a hot gas, in a counter flow arrangement. The hot gas enters the cooler at 350ºC and leaves at 100ºC. The cooling water enters the cooler at 10ºC.

The flow rate of the gas is 200 kg/hour and that of the water is 1400 kg/hour.

The wall thickness of the pipe may be ignored. Calculate EACH of the following:

(a) The exit temperature of the water

(b) The log mean temperature difference

(c) The length of the cooler.

Note: For cooling water C_p = 4.19 kJ/kg K

For the hot gas C_p = 1.13 kJ/kg K

The Inner surface heat transfer coefficient = 0.3 kW/m²K

The outer surface heat transfer coefficient = 1.5 kW/m²K