ME 414 – TEAM #1J E N N I F E R H A C K E R

J E S S E K E N D A L L

C H R I S T O P H E R R O G E R S

B R A N D O N R O D R I G U E Z

A L E K V A N L U C H E N E

Heat Exchanger Design

Problem Statement

Design a heat exchanger that cools a corrosive chemical with water properties from 45 C to 25 C with a mass flow rate of 220,000 kg/hr using city water at 22 C with variable mass flow rate.

Design Requirements

Heat Exchanger Length is less than 7 mHeat Exchanger Diameter is less than 2 mMinimize Pressure Losses in both shell and

tubeMinimize Weight

Variable Reduction

Tube & Shell Material – Stainless Steel

Tube will carry corrosive material for ease of cleaning

Counter flow was selected due to increase efficiency

Single pass selected due to lower pressure drop, small cooling requirement, and cost

Shell thickness was selected to minimize weight and handle maximum pressure of the heat exchanger.

Variable Reduction Cont …..

Center tube diameter was selected to be the same size as other tubes to reduce cost

For efficiency and ease of cleaning a square pitch was chosen

The pitch angle was chosen to be 90 deg since the angle did not affect the design parameters

The MATLAB program chose the number of tubes based on the shell diameter

To Baffle or Not?

Advantages Higher Heat Transfer

Disadvantages Higher Pressure Loss Increased Weight

Since the chemical only required a small amount of cooling (20 C) the baffles were not needed for the gain in heat transfer.

Main Effect Plots - Q

Main Effect Plots – ΔP Tube

Main Effect Plots – ΔP Shell

Main Effect Plots – Weight

Pareto Chart

Minitab Optimization

End Results

Initial Values Optimized Values UnitsWeight 4000 4022 kgΔP Shell 30000 29930 PaΔP Tube 15000 14630 PaHeat Transfer 3250000 32510000 W/m^2

Shell Mass Flow Rate

85Counter Flow or Parallel CounterNumber of Tube Passes 1Baffles NoShell Inner Diameter 0.6858Shell Thickness 0.001Shell Material Stainless SteelTube Material Stainless SteelTube Outer Diameter 0.00635Center Tube Diameter 0.00635Tube Thickness 0.000457Tube Length 5.5Number of Tubes Calculated by MATLABTubing Pitch SquareTube Layout Angle 90

Questions

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