An Approach to Heat Recovery in Rural Alaska

1. An Approach to Heat Recovery in Rural Alaska • Introduction • Background – Maintenance & Repair • Small Scale: 50 kW to 3500 kW • Heat Recovery: SAVES Fuel - NOT Primary Heat • Keep it SIMPLE

2. Rules of Thumb • 1/3 Electricity : 1/3 Jacket Water : 1/3 Exhaust • 2000 BTU/kW-Hr (jacket water) • 100,000 BTU delivered Heat = 1 gallon #1 Diesel • 0.3 x Power Plant Annual Fuel Use x 0.6 • Pumping Energy Costs <= 10% Fuel Value • Size System Flow for 2/3rds Peak Load

3. End-Users • Water Plant / Washeteria • Schools • Public Facilities (Clinics, City Offices, Rec Centers) • Ice / Cold Storage (low temp absorption chiller)

4. Design Considerations • Power Plant Diesels (heat rejection, pump capacity) • No In-Line Booster Pumps • Secondary Pumped Loop • Power Generation = Primary  • End-User Heat Loads • Historical Fuel Use Based • HDD and Composite UA

5. Design Considerations cont’d • Pumping • Minimize Pumping Energy (valves/restrictions) • Redundancy • Arctic Piping • Welded steel, HDPE jacketed • Copper where indoors/utilidors • Instrumentation • Thermometers (thermo-wells) • Pressure Gauges (isolation valves) • Air Vents (minimize + isolation valves)

6. Design Considerations – cont’d • Air Control • Air Eliminator (rol-air-trol vs. air scoop) • Expansion Tank Sizing (40F or –40F) • Pre-charge (set for specific application)  • Arctic Piping Loop Fluid • Ethylene / Propylene / Water  • MAINTAINABILITY / ACCESS • Equipment Location • Valving

7. End-User Connections • Direct Connection • Full Boiler Flow thru Heat Exchanger • Heat Availability close to Boiler Capacity • Partial Boiler Flow thru Heat Exchanger • Heat Availability << than Boiler Capacity

8. Equipment • Heat Exchangers • P&F Clip on Gaskets (>70 gpm) • Brazed Plate (<70 gpm) • Valves • Lug Style Butterfly • Full Port Ball Valves • (no gate valves) • Arctic Piping • Preinsulated Arctic Pipe Package

9. Daily Operations • Daily Log • Monitor and Record • Temperatures, Pressures, Pump Operation • Check Glycol Concentration & Inhibitors

10. Typical Jacket Water Heat Rejection of Diesels

11. Typical Jacket Water Heat Rejection of Diesels (continued)

12. 6-Port P&F Heat Exchanger

13. Wood Boiler & Heat Exchanger

14. Electric Boiler & Heat Exchanger

15. Inaccessible Heat Exchanger

16. Inaccessible Heat Exchanger

17. AVEC Ambler Plant

18. AVEC Kiana HRM

19. AVEC Kiana HRM-radiators

20. AVEC Anvik Heat Recovery

21. AVEC Anvik Heat Exchanger

22. IASD Anvik Heat Recovery Module

23. IASD Anvik Heat Exchanger

24. Selawik Power Module

25. Heat Exchanger & BF-Valve

26. Secondary Pumped Loop HXR

27. AMOT Tree

28. AVEC SelawikHRM-before

29. AVEC SelawikHRM-New Style