Heat Exchange Design and Optimization Project

Presented: May 6th, 2010

Professor: Mr. Toksoy

Group Members: Nathan Dart

Andrew KinneyPaul Thompson

Joe Sullivan Christian Watness

Problem Statement:

Design Criteria/Assumptions: Mass flow rate = 220,000 kg/hr

Material properties of this chemical product can be approximated as water

Cooling of the chemical product will be achieved by using treated city water

City water is available at 20 C⁰

Exit temperature of city water from the heat exchanger is a function of the selected mass flow rate

Using a heat exchange reduce a liquid chemical by 20 C via ⁰city water.

Design Optimization Goals:

Chemical must be cooled from 45⁰C to 25 ⁰C.

Length of heat exchanger must not exceed 7 meters.

Diameter of shell must not exceed 2 meters.

Minimize heat exchanger weight.

Minimize heat exchanger pressure drop.

Initial Parameters:Funnel Effect

Tube ODCity Water FlowTube LengthTube ThicknessTube Layout & AngleTube MaterialTube PitchShell Mass Flow Rate

Shell Material Shell Thickness City Water Flow Rate Counter or Parallel

Flow Shell ID Baffles – Yes or No Baffle Spacing

Main Effects Plot: Weight

Main Effects Plot: ΔP Shell

Main Effects Plot: ΔP Tube

Main Effects Plot: Q Calculated

Pareto Chart: Weight

Standardized Effects: Weight

Pareto Chart: ΔP Shell

Pareto Chart: ΔP Tube

Pareto Chart: Q Calculated

Standardized Effects : Q Calculated

Standardized Effects : Q Calculated

Optimized Results: HE Pressure Drop======================================Shell Side Delta-P = 12330.12 Pa Shell Side Delta-P = 12.33 kPa Tube Side Delta-P = 2412.77 Pa Tube Side Delta-P = 2.41 kPa ======================================Shell Side Pump Power = 0.31 kW Tube Side Pump Power = 0.11 kW

Heat Exchanger Weight======================================Shell Weight = 96.79 kg Tube Weight = 887.29 kg Shell Fluid Weight = 1363.08 kg Tube Fluid Weight = 873.20 kg

Total HE Weight = 3220.36 kg

Heat Exchanger Inlet & Outlet Temperatures (Celsius) ========================================== Inlet Outlet Delta Bulk Wall Tube 45.00 25.00 20.00 35.00 30.55 Shell 20.00 32.22 -12.22 26.11

Overall Heat Transfer Coefficient======================================U (Tube Outside Area) = 815.25 W/m2.C

Heat Transfer Rate======================================Desired Heat Transfer Rate = 5106263.80 WCalculated Heat Transfer Rate = 5105087.64 W Difference = 1176.16 WDesired-to-Calculated Ratio = 1.00

Material Selection Reasoning: Cost of Shell (96.79 kg = 213.385 lbs)…

•Stainless Steal 1.04/lb = $221.92 Total

•Aluminum.84/lb = $179.24 Total

Cost of Tubes (N = 8,142)…

•Aluminum $1,117,489.50$

•Stainless Steal $1,384,615.20

Therefore, Aluminum was chosen for the tube material due to its low weight. In addition, Stainless steal was chosen as the shell material to provide a longer shell life.

Referenced:

Toksoy, John. ME 414 Thermal-Fluid Systems Design. Department of Mechanical Engineering, IUPUI, Indianapolis, IN, Spring 2010.

OnlineMetals.com. (n.d.). Retrieved May 6, 2010, from htttp://www.onlinemetals.com/basket.cfm

Questions?