1. 1 ME421 Heat Exchanger Design Drain Water Heat Recovery System Project Presentation Group #5

2. 2 OUTLINE Problem Definition Problem Definition Available Solutions Available Solutions Proposed Solution Proposed Solution Application Data Application Data Solution Procedure Solution Procedure Results and Discussions Results and Discussions Conclusion Conclusion

3. 3 PROBLEM DEFINITION Heat wasted during shower

4. 4 AVAILABLE SOLUTIONS Gravity Film Heat Exchanger(GFX) Gravity Film Heat Exchanger(GFX)

5. 5 PROPOSED SOLUTION Gasketed Plate Heat Exchanger: High Area/Volume Ratio High Area/Volume Ratio Low Cost compared to GFX Low Cost compared to GFX Easy to clean Easy to clean Flexible Design Flexible Design

6. 6 APPLICATION DATA ParameterMagnitude Unit (SI) Hot Inlet Temperature 37°C Hot Outlet Temperature 23°C Cold Inlet Temperature 11°C Cold Outlet Temperature 25°C Cold Water Mass Flow Rate 0.2kg/s Hot Water Mass Flow Rate 0.2kg/s Hot Side Fouling Factor 0.00005m.K/W Cold Side Fouling Factor 0.0000086m.K/W

7. 7 SOLUTION PROCEDURE Initial Assumptions: Steady state and steady flow processes Steady state and steady flow processes Plate dimensions based on MIT 522 [1] Plate dimensions based on MIT 522 [1] L v, L h, b, t, D p, β, Φ L v, L h, b, t, D p, β, Φ Negligible potential and kinetic energy change Negligible potential and kinetic energy change Equal inlet & outlet mass flow rates Equal inlet & outlet mass flow rates Single pass counter flow arrangement Single pass counter flow arrangement Safety factor Safety factor

8. 8 SOLUTION PROCEDURE (Cont’d) Procedure: Iteration method to find N t Iteration method to find N t U A e N t G Re Nu h U U A e N t G Re Nu h U Rechecking of N t using calculated U Rechecking of N t using calculated U Pressure drop and pump power calculations Pressure drop and pump power calculations Comparison of ΔP limit and ΔP calculated Comparison of ΔP limit and ΔP calculated

9. 9 RESULTS and DISCUSSIONS N t ranging between 3 and 11 Pressure Drop (Pa) Pressure Drop vs Number of Plates (N t )

10. 10 RESULTS and DISCUSSIONS (Cont’d) β values : 30 °,45 °,50 °,60 °,65° Heat Recovery (W) Heat Recovery vs Chevron Angle (β)

11. 11 RESULTS and DISCUSSIONS (Cont’d) Pump Power (W) N t ranging between 3 and 11 Pump Power vs Number of Plates (N t ) Pump Power (W) Pump Power vs Number of Plates (N t ) Pump Power (W)

12. 12 RESULTS and DISCUSSIONS (Cont’d) β values : 30 °,45 °,50 °,60 °,65° Pressure Drop (Pa) Pressure Drop vs Chevron Angle (β)

13. 13 RESULTS and DISCUSSIONS (Cont’d) ParameterMagnitude Number of Plates 7 Effective Heat Transfer Area 1.463 m 2 Fouled Heat Transfer Coefficient 933 W/m 2.K Required Pump Work 24.5 W Heat Transfer Rate 1.17 x 10 4 W Net Heat Recovery 1.17 x 10 4 W

14. 14 CONCLUSION Preheated. Preheated.