ME 414 - THERMAL FLUID SYSTEM DESIGNSHeat Exchanger Final Project

PROBLEM STATEMENT

Parameters of Heat Exchanger Mass flow rate = 220,000 kg/hr Working fluid is treated as water Working fluid enters at 45 ºC Working fluid exits at 25 ºC

Design Limits of Heat Exchanger Cooling fluid is city water Cooling fluid enters at 20 ºC Max length is 7 meters Max shell diameter is 2 meters

GOALS OF DESIGN OPTIMIZATION

Achieve Heat Transfer Requirements 5.11 MW

Minimize Pressure Drop This increases the efficiency of the heater

exchanger Direct result is lower energy requirements, which

means lower energy costs

Minimize Weight This is directly proportional to the cost More material = more money

FUNNEL EFFECT

Design Requirements All variables available

Run OFATS 12 variables

Run DOE 1 and DOE 2 6 variables

Run DOE 3 4 variables

Optimize Pareto Charts

DESIGN OF EXPERIMENT VARIABLES

DOE 1 Shell Internal Diameter Tube Outside Diameter Tube Length Tube Thickness Mass Flow Rate

of Cooling Fluid Number of Tube Passes

DOE 2 Use of Baffles Baffle Spacing Baffle Cut Counter Flow versus

Parallel Flow Shell Material Tube Material

RESULTS OF DOE 1

RESULTS OF DOE 2

REMAINING VARIABLES

Shell Internal Diameter Tube Outside Diameter Tube Length Tube Thickness Counter Flow Shell Material

RESULTS OF DOE 3

PARETO PLOTS

OPTIMIZATION

BEFORE OPTIMIZATION

Variables Shell Internal

Diameter = 0.5 m

Tube Outside Diameter = 0.003 m

Tube Length = 5.95 m

Tube Thickness = 0.002m

Characteristics q = 5.11 MW

Weight = 2473 kg

Tube Side Pressure Drop = 3680 Pa

Shell Side Pressure Drop = 2321 Pa

AFTER OPTIMIZATION

Variables Shell Internal

Diameter = 0.52 m

Tube Outside Diameter = 0.035 m

Tube Length = 4.87 m

Tube Thickness = 0.04m

Characteristics q = 5.11 MW

Weight = 1365 kg

Tube Side Pressure Drop = 163 Pa

Shell Side Pressure Drop = 1344 Pa

CONCLUSION

Engineers can benefit greatly from optimization.

The combination of Matlab and Minitab can save time and money in design.

QUESTIONS

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