Question

1 CPD4701 Assignment 2/2019 Question 2 shell and-tube heat exchanger was designed for the following service: Cold stream Hot stream Crude Oil Fluid Cooling water Tube side Stream allocation Shell side Mass flow rate (kg/s) 110 30 Inlet temperature (C) 90 Outlet temperature (C) Heat capacity (J/kg K) Density (kg/m2) Viscosity (Pa-s) Thermal conductivity (W/m-K) Fouling factor (m2 CW) 40 50 2177 4187 787 995 0.72-10 1.89-103 0.122 0.59 0.0002 0.0004 The shell and tube heat exchanger has the following specifications: One (1) shell pass Shell Inside diameter: 1.372 m Tubes: Four (4) tube passes 2 344 tubes of 19.05 mm OD,1.25 tube pitch ratio, square pitch Tube wall thickness = 1.65 mm Tube length= 4.877 m Tube material kw = 50 W/m K Baffle spacing of 620 mm with a 25 % cut Baffles: Tube side: 1-3 m/s Shell side: 0.5-1 m/s Linear velocity range: f the hot fluid increased by 20%. Nonetheless , the inlet After a debottlenecking exercise, the flowrate and outlet temperatures must be maintained at their current values. The pumps feeding the exchanger were designed to allow for an increase in the pressure drop of both fluids must not exceed 90 kPa both fluids. However, the pressure drops 2.1 Calculate the original and the new heat transfer duties. (4) 2.3 Rate ne area ava anger for the new service (20% increase in the flow rate of hot fluid Determine if the existing exchanger will meet the area requirements and the pressure drop requirements. 2.4 If the existing exchanger does not meet the requirements, how can the existing exchanger be modified to meet the requirements. Show (35) calculations (14) [55 TOTAL: 95 UNISA 2