https://facilitiesservices.utexas.edu/buildings/UTM/0448 Field Trip Next Tuesday (May 2nd) PPE 3.3 04 conference room at 11 am https://facilitiesservices.utexas.edu/buildings/UTM/0448

Lecture Objectives: Finish with thermal storage systems Learn about pumps and plumbing

Thermal storage system in parallel- requires stratified tanks

Stratified chilled water tanks diffuser geometry Challenge: “Pull” large amount of energy without disturbing stratification

Temperature and dynamics Temperature at outlet during the changing cycle of the tanks

Installation of thermal storage system when in series Upstream Downstream • 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!

District heating and cooling systems Require expertise in Plumbing Pumps Control

Plumbing - System Curves A+B A B A+B A B V A B V A B Parallel Serial

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

Pumps Raise pressure and produce flow Main type Centrifugal Example of Turbine pump Base mounted Reading (textbook) Page 3-36 - 3-45 Inline http://www.taylor- engineering.com/downloads/cooltools/EDR_De signGuidelines_CoolToolsChilledWater.pdf

Curve for Multiple Pumps

Changing Pump Speed

Primary/Secondary and Tertiary Pumping Reading Assignment: 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

Hydronic systems for district cooling/heating and buildings Constant-Flow System, Single Chiller, Single Coil Constant-Flow System, Single Chiller, Multiple Coils Mixing valve that control by-pass flow Major pumping force is the chiller pump

Control of coil temperature Mixing valve that control the flow through the coil Flow Variation as a Function of Valve Position Same pressure drop like a cooling coil Major pumping force is the chiller pump

Multiple chiller (or boilers) Parallel Serial

Primary-Loop Only Variable Speed Flow Single chiller Multiple chillers

Primary and Secondary Loop Variable Flow Design Parallel chillers Serial chillers

Large Plant or Building Distribution Systems Primary/Secondary Loops with Variable Flow and Distributed Pumping

Primary/Secondary and Tertiary Pumping

Primary Pump Arrangements Dedicate a pump for each chiller Provide a common header for the pumps

Coil Pumping Strategies Variable speed pumps vs. Single pas Valve vs. Mixing valves vs. Diverting Valves

Impact of plumbing on a cooling coil

Plumbing Arrangement in Building’s hydronic systems Radiators Baseboard heaters Fan coil systems

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

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%2Fdownload.php%3Ffile%3Dhegberg.pdf&ei=IvcqU_O1KMuE2AWgloHgDA&usg=AFQjCNFRAMzPnbzDpAluhyk4l8u_SKKTdw

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