Knowledge is Power Belimo Energy Valve™CHW DELTA T MITIGATION STUDY

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2014 AHR Expo Innovation Award” Winner in the Category of Building Automation

The Belimo Energy Valve™ won the “Technical Innovation of the Year – Products” at the BCIA Building Controls Industry Association Awards.

BOB RYBKABELIMO AMERICAS908 397 5960

Delta T Mitigation StrategiesEnergy Valve Site Study

• Dynamic Balancing Control Valve Technology• Chilled Water delta T Study• Chilled Water System Design• AHU Coil• Beta Site Study• Correcting Low delta T• Data Analysis and Optimization• Additional Applications

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Water exits valve

Pressure is P2 (low)

Water enters valve

Pressure is P1 (high)

Pressure Independent Control Valve

Water passes through regulator, disc, and ball

Pressure Drops

Ports sense pressure drop and transfer it below regulator

Low pressure pulls regulator down, against the spring force

Operational theory

ELECTRONIC PRESSURE INDEPENDENT VALVE1/2’’– 6”, 1.65 thru 713 GPM

Actuator

Valve

Flow Sensor

ELECTRONIC PRESSURE INDEPENDENT VALVE WITH WATER DELTA T MANAGMENT

½’’ – 2’’ NPT - 1.6 thru 76 GPM2.5” – 6” FLANGED - 90 thru 713 GPM

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Library Case Study

• Case Study Issues• Coil delta T reported as 6 Degree F• Over pumping• Low delta T Syndrome at Chiller Plant

6 AHU units, 153,000 sq-ft

Chilled Water SystemPeak Load 26,000 Tons

• UNIVERSITY CAMPUS STUDY

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* From 2008 Chilled Water Delta T Study

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Savings by Eliminating Causes of Low Delta T (30,000 Ton Plant)

• Recommend implementing chilled water delta T improvement projects across the campus.

Component Annual Energy Savings

Annual Cost Savings

Chiller Steam 10,887 Mlbs $181,000.00

Chiller Electric 2,576,000 kWh $412,000.00

CHW Pump Electric 2,334,000 kWh $373,000.00

CW Pump Electric 2,417,000 kWh $387,000.00

CT Fan Electric 740,000 kWh $118,000.00

TOTAL SAVINGS $1,471,000.00

25% of Total

Design

• Flow and delta T are inversely proportional; for a given load, when delta T drops flow has to increases.

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T24TonsGPM

T1224TonsGPM 800

2TonsGPM 800

Tons2GPM 800

400Tons

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Typical Chilled Water System

System DataChiller #1 Load = 90%Chiller #2 Load = 0%Loop Flow = 360 GPMChiller ∆T = 12˚F

Design: 400 Ton CHW System @ 12˚∆T

Chiller200 tonsVFD Pump

VFD Pump Chiller200 tons

180 Ton Load (45%)

42˚

360 GPM Loop Flow

CHWS

90% LoadIncrease flow by 15%

CHWR

54˚

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Typical Chilled Water System

System DataChiller #1 Load = 45%Chiller #2 Load = 45%Loop Flow = 414 GPMChiller ∆T = 10.4˚F

Design: 400 Ton CHW System @ 12˚∆T

Chiller200 tonsVFD Pump

VFD Pump Chiller200 tons

180 Ton Load (45%)

42˚

414 GPM Loop Flow

CHWS

45% LoadIncrease flow by 15%

CHWR

52.4˚

Chiller200 tons

45% Load

An additional pump and chiller were started to meet the flow demand, not cooling demand!

Causes of Low Delta T

– Control valves oversized– Controlling the water valve using air temp– Inadequate balancing procedure– Non-dynamic balancing– Changes to piping system

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Not the Solution

• Deny or Choke Valve, will not allow a coil to run as designed. This application will negate proper de-humidification and comfort.

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Library Case Study

• Case Study Issues• Coil delta T reported as 6 Degree F• Over pumping• Low delta T Syndrome at Chiller Plant

6 AHU units, 153,000 sq-ft

Case Study

• AHU-6, CHW delta T with Belimo SL System Globe Valve test delta T control deactivated.

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Case Study

• AHU-6, CHW delta T with delta T control active-Globe Valve test.

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Case Study Setup

• 5 Flow Meter/Delta T Control Valves• 1 Tandem Venturi Valve with Delta T Control• Chilled Water is designed to run through a coil at a

designed temperature drop to supply air conditioned cooling air and to de-humidify. i.e. Water delta T=12 degrees F.

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Delta T and GPM control valve2.5” – 6”, 90 thru 713 GPM

• The Valve is a pressure independent control valve that optimizes, documents and proves water coil performance by correcting low delta T.

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Actuator

Valve

Magnetic Flow sensor

Temperature Sensors (for supply & return water)

Valve Operation

• Pressure independent, Mag flow meter maintains proper flow.

• Delta-T Manager will maintain design Coil delta-T.• Delta T will stay constant eliminating overflow.• The Energy Valve’s GPM meter, and temperature

sensors add no additional DDC points to a system.

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New Definitions

• Power Saturation Point– Point beyond which coil cannot yield additional

heat transfer regardless of increased flow.• Waste Zone

– Range beyond the “Power Saturation Point”.

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AHU-6 Power Curve: July 4, 2011 (data is PI valve function only)

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AHU-6 DT Curve: July 4, 2011 (data is PI valve function only)

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Power Saturation & Waste Zone

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Energy Valve Delta-T Manager Operation

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DDC SIGNAL

Pump Savings Example24% Flow Savings = 56% Energy Savings

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0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

0.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00 90.00

12.57, 43.0910.27, 56.60

Pump flow Savings= (56.6-43.09)/56.6 = 24% Mechanical Energy Savings

=1-((1-.24) power 3)=56%

T

Flow [GPM ]

∆TCurve

T

Hours Delta T Manager Active(Summer 2011)

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MIT, Haden Library Whole Building Results

• 2011 vs. 2010 Flow• 8/9-10/9 2010 6.15 F T • 8/9-10/9 2011 12.14 F T• From whole building meters, Metering data PI archive• Tonsx24/GPM= Weighted Average delta T

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6 AHU units, 153,000 sq-ft

Case Study Findings

• The delta T limiting is especially effective on coils that display “power saturation”

• Overall reduction of chilled water flow.• Significant energy savings are realized in

mechanical pumping energy with Delta-T Manger.

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Library Saving Calculations

• Using Data supplied by the Campus Engineering, increasing water delta T from 6 to 12 degrees. The potential savings for calendar year 2011 are as follows:– 2011 had 1005 COOLING D-DAY»$12,529.00 CHW

PUMP ALONE (25% of total savings).– Plant savings, turning off chillers, condenser pumps

and fans would equal a potential savings of $50,116.00.

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Chilled Water Delta T management technology

• Technical Summary• Maximize coil performance• Monitor savings at the coil level• Documented commissioning of coil• 13 month data archive

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Belimo Energy Valve

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• Features & Benefits

Knowledge is Power

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Process Order

1. Benchmarking

2. Data Acquisition

3. Analysis

4. Optimization

BenchmarkingStep 1

• Building Design• The first iteration of benchmarking is the Engineer’s design

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Data AcquisitionStep 2• Delta T and Flow data

– Flow– Delta T– Energy Output– Power Output– Totalized Energy

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Data AcquisitionStep 2

• Data Export and the Excel Tool• Energy Valve

• Data Logging and Storage• Up to 13 Months of Data• Export to .csv file format

• Excel Tool • Import .csv in to Excel Tool• Power Curves• Charts, Graphs, Trending

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Data AcquisitionStep 2

• Web View – Live Trending View• Live Trending

• Temperature• Flow (GPM)• Power (kW)• Up to 1hr of Data

• Features• Real Time Data• Export to .csv

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Data AcquisitionStep 2

• Web View – Live Trending View• Network Communications

• BACnet MS/TP• BACnet IP• TCP/IP• MP-bus

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Data AcquisitionStep 2Supported BACnet Objects

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Data AnalysisStep 3Analyzing the Power Curve

© Belimo, 2012

OptimizationStep 4

• Web View - Parameterization Settings View• Networked, Communicate via Web• Real Time Configuration• Real Time Data

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OptimizationStep 4

• ZTH-2 - Parameterization Tool

• Quick Programming• Quick Reconfiguration• Fast Commissioning• Hand Held Local Display

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Hot Water Applications

• High Efficiency Condensing Boilers• Boiler efficiency 98%• Combustion gas 18°F above return water temp• Return temperature should be below 110°F

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Thank You

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