Efficiency Vermont is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.

This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Learning Objectives

At the end of this program, participants will be able to:

Understand the effectiveness of using a new technology refrigerant flow meter to optimize chiller operation

Understand how flow can be used to identify actual KW/ton energy use rather than relying on energy ratings that use ideal laboratory conditions

Select the proper Kw motor and current sensors for a wide range of system load.   Understand how a refrigerant flow meter is used to determine a refrigeration system's total operating tonnage.

Course EvaluationsIn order to maintain high-quality learning experiences, please access the

evaluation for this course by logging into CES Discovery and clicking on the Course Evaluation link on the left side of the page.

Chiller Optimization

Utilizing A

Refrigerant Flow Meter

Checking Energy Usage - ChillerChecking Energy Usage - Chiller

• We need accurate measurements of the total We need accurate measurements of the total power of the chiller.power of the chiller.

• Allows for a direct measurement methodAllows for a direct measurement method

• Accurate measurements of the total tons of Accurate measurements of the total tons of work the machine is producing. work the machine is producing.

• Fewer monitoring points than standardFewer monitoring points than standardmethods currently usedmethods currently used

Standard Method to Determine Refrigeration TonsStandard Method to Determine Refrigeration Tons

AmpsAmps

VoltsVolts

TT11

PP11

TT33

PP33

TT22

Refrigerant Flow to Determine Refrigeration TonsRefrigerant Flow to Determine Refrigeration Tons

AmpsAmps

VoltsVolts

TT11

TT33

GPMGPM

CHWS

Evaporator Chiller Barrel

CHWR

N/C

N/O

N/O

N/C

N/O

USFT-CS-04

USFT-R-.75

RTD RTD

Monitoring Points

Chilled Water Supply Temperature

Chilled Water Return Temperature

Chilled Water Flow - GPM

Refrigerant Temperature

Refrigerant Flow - GPM

Chiller Kw

12

54

3

6Kw Meter & Disconnect

Monitoring Points - Kw/Ton

Not to Scale

VaporizationVaporization

VaporizationVaporization

Can be used in conjunction with a chilled water flow meter Can be used in conjunction with a chilled water flow meter with temperature sensors to compare the efficiency of the with temperature sensors to compare the efficiency of the chiller barrel itself.chiller barrel itself.

1.1. Could be used as a preemptive method to Could be used as a preemptive method to schedule chiller maintenance.schedule chiller maintenance.

2. Could save considerable maintenance 2. Could save considerable maintenance costs by only scheduling tube cleaning costs by only scheduling tube cleaning when necessary.when necessary.

Two ultrasonic transducers are positioned and angled as to transmit and receive sound pulses launched at a flat reflection point located on the opposing side of the pipe.

The flight time of the sound pulse from one transducer to the other is shortened if the pulse is launched in the direction of flow and increased if launched opposite to the direction of flow.

By alternating the transmitting and receiving transducers, the difference in these transit times can be used to calculate the velocity of the flow.

ASIC (Application Specific IC ), which provides all the functions required to alternately transmit and receive sonic pulses and measure the transit times to picosecondaccuracy. The ASIC implements the “Sing Around” method to launch and receive pulses, each received pulse initiating the next transmitted pulse. On any one measurement, a number of such cycles are used to accumulate the individual transit times which are then divided by the number of cycles to give an average of these measurements.

     

Metering Chiller Performance Metering Chiller Performance ExampleExample

BTUH = 500 x GPM x T /12,000

BTUH = 500 x 88.5 GPM x 4.5°F T = 199,125

Tons = 199,125 BTUH / 12,000 BTUH = 16.59 Tons

kW per ton = 1kW / 16.59 Tons = .0602 kW / Ton

Hybrid Free Cooling Chiller

CHWS

Liquid LevelSensor

Receiver

Evaporator Chiller Barrel

CHWR

Muffler

Liquid LevelSensor

N/C

N/O

N/O

N/O

Discharge Pressure

Refrigerant Temp Out

Refrigerant Temp - In

Suction Temp

Condenser Fan # 1

By-Pass Check

N/C

Condenser Fan # 2

LRP

N/O

US Patent Pending No. 11/562,805US Patent Pending No. 11/562,805

Kw Usage with Mechanical CoolingKw Usage with Mechanical Cooling

System Head Pressures set from factory @ 225 PSIGSystem Head Pressures set from factory @ 225 PSIG

Kw Usage with Mechanical CoolingKw Usage with Mechanical Cooling

System Head Pressures adjusted to 125 PSIGSystem Head Pressures adjusted to 125 PSIG

““Floating the Head Pressure”Floating the Head Pressure”

Reduced Pressure Reduced Pressure Readings Readings

Kw Usage with Hybrid Free CoolingKw Usage with Hybrid Free Cooling

Petra chiller- kW Usage

0

1

2

3

4

5

Jan 24 - 30, 2006

kW

Date/Time Velocity (ft/s)Flow (gpm)

Mass flow (lb/m)

1/24/2006 19:00:33 4.29 150 3.786 ID (in)

1/24/2006 19:02:34 4.28 150 0.078179 area (sq.ft)

1/24/2006 19:04:33 4.23 148 7.480519 gal/cu.ft.

1/24/2006 19:06:34 4.21 148

1/24/2006 19:08:33 4.22 148

                                                                                                                                                 

     

1/24/2006 19:10:33 4.21 148

1/24/2006 19:12:33 4.22 148

1/24/2006 19:14:34 4.27 150

1/24/2006 19:16:34 4.28 150

1/24/2006 19:18:36 4.28 150

1/24/2006 19:20:33 4.29 150

1/24/2006 19:22:33 4.28 150

1/24/2006 19:24:34 4.26 150

1/24/2006 19:26:33 4.22 148

1/24/2006 19:28:35 4.20 147

1/24/2006 19:30:33 4.20 148

1/24/2006 19:32:34 4.21 148

1/24/2006 19:34:34 4.22 148

1/24/2006 19:36:34 4.20 147

Ultrasonic Water Flow Measurements – Efficiency Vermont Ultrasonic Water Flow Measurements – Efficiency Vermont

FlowRate: Chilled Water Flow

142

144

146

148

150

152

154

Jan 24 - 30, 2006

gp

m

Questions