1. Lecture Objectives: Finish with thermal storage systems Learn about plumbing systems

2. Construction and benefits Active Passive (wall)

3. Modeling (stratified tank) Write energy and mass balancer equation for each section

4. Installation of thermal storage system DownstreamUpstream Increases chiller efficiency Increases chiller capacity Overall system efficiency ??? Decreases storage capacity Simplifies system layout ….. Decreases chiller efficiency Decreases chiller capacity Overall system efficiency ??? Increases storage capacity …… Does not allow chiller shut down!

5. Plumbing Systems - Hydronic Terms Head loss Open-loop vs. closed loop Open System Closed System Pump h Cooling coil in AHU Chiller Pump

6. Is this open or closed system ? Cooling towers

7. Relationship between velocity in a pipe and pressure drop Δp ~ v 2 Δp = Constant × v 2 Δp [Pa or ft water ] v [m/s or fpm] larger pipe smaller pipe Required power (P) for the pump P = V × Δp P –power [W], V –volume flow rate [m 3 /s], v – velocity [m/s] Δp – pressure drop [Pa] Δp ~ v 2 (Δp ~ V 2 – when same pipe is used ) P ~ V × V 2 – when same pipe is used P ~ V 3 P 2 /P 1 = (V 2 /V 1 ) 3 For the same pipe When different pipe is used for the same flow rate: For the same flow rate V Reduction of D: D1D1 D 2 = D 1 /2 A 1 V 1 P 1 A 2 =1/2 2 A 1 V 2 =2 2 V 1 P 2 /P 1 = (D 1 /D 2 ) 4 - for the same flow rate or 50% smaller diameter of the pipe for the same flow rate wee have: 4 times larger velocity 16 times larger pressure drop and 16 times lager power for the pump

8. Head Loss

9. Fittings

10. Pumps Raise pressure and produce flow Main type Centrifugal Inline Base mounted Example of Turbine pump Reading (textbook) Page 3-36 - 3-45

11. Pump curves NPSHR = Net Positive Suction Head Required

13. Changing Pump Speed

14. Net Positive Suction Head (cavitation)

15. Curve for Multiple Pumps

16. System Curves A B ∆p V A+B Parallel A B A B ∆p V A+B A B Serial

17. Find a system curve for this plumbing configuration

18. Primary/Secondary and Tertiary Pumping (schematics A&B below) Taylor, S., P. Dupont, B. Jones, T. Hartman and M. Hydeman. 2000. Chilled water plant design guide. San Francisco: Pacific Gas & Electric Company. http://www.taylor- engineering.com/downloads/cooltools/EDR_DesignGuidelines_C oolToolsChilledWater.pdf Reading Assignment:

19. System balancing BOILER HC2 AHU1 AHU2 HC1 pump 100 ft 1000 ft 2 gpm 10 gpm 10 ft

20. Valves Section 5-14 and 6-15 in the textbook Types Butterfly Valves Ball Valves Globe Valves Three way valves

21. Valve Sizing and Flow Coefficient Cv value: in liter/hour or…. in Pa Control Valve Selection For Hydronic Systems reference: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact= 8&ved=0CCUQFjAA&url=http%3A%2F%2Fbookstore.ashrae.biz%2Fjournal%2Fdow nload.php%3Ffile%3Dhegberg.pdf&ei=IvcqU_O1KMuE2AWgloHgDA&usg=AFQjCNF RAMzPnbzDpAluhyk4l8u_SKKTdw

22. Control Valve Selection For Hydronic Systems Before DC we tried to do this Valve authority